The second game in the folder you sent me (Taric 8, you are bottom with an EZ vs a Graves/Nami). Before I even start the replay, I am going to go over some stuff unrelated to your play. You are first pick in the game. If you are picking support that early, Taric is a very strong choice. Support is just as prone to being countered as mid or top, so he is a safe pick. A lot of people will pick stuff like Sona first, that is just asking to be rolled over. Your AD Carry picked Ezreal, which is not the best pick with Taric in lane, but does decent against the enemy Nami, so I can see it. Something like Vayne or Graves would have been better for your lane though. Whatever, not your fault. Overall, I think the enemy team has a slightly stronger lane, but nothing a Taric/Ezreal shouldn't be able to handle.
If you were not running a more defensive mastery page for this matchup, you should have been. Even as Taric, Graves hurts. Bush control will be big, make sure you have the Explorer ward to help that little bit in lane or to cover from invade.
Ok, on to the replay. First things first, they have no wards. If you didn't tell your jungler that very first thing when they showed their faces, you should have. If you did, good job. Second you let Nami get control of the lane bush. You started with 3 wards. They push the lane fast and you decide to leave the bush since Graves is on the far side of the lane. That is fine, but leave a ward as you go. Nami will just peg you from inside that bush if you don't. She started Doran's Ring, she hurts a little. This ends up giving them first blood when she manages to Q both you and your ADC. Was it the only reason? No. Your Ezreal should have had Arcane shift, he was level 2 and against a lane with a strong, hard CC and short range burst. You can't control that though. You CAN give him vision and save your stun. You had used it on Graves for no reason right before the kill. You didn't have shatter to follow up with since you were level 1 and he wasn't being aggressive, so it was just a waste. You probably could have exhausted and saved your carry, but I can't honestly say I would have realized my carry was going to flat out die right there, so I get why you didn't. Whatever.
4:35 - Master Yi waited in tri a minute, then decided to lane gank. This implies to me you didn't tell him they had no wards. He should have noticed, but just assume he won't notice it. Jungler has to keep track of every lane, you only have one at the moment. Again, if you told him, my bad. He is dim. Gank goes...about as well as it could have? It was never going to result in a kill. If you had tossed one of your wards (you still have 2) in their lane bush, you could have waited for Nami to be a bit closer, but I still doubt it would have resulted in a kill. 2 flashes down is still good.
6:36 - Don't let Graves shoot your carry! Screw him. Stun him. Shatter, free damage then roll out. They have a bit of a minion wave, but you are Taric, you can handle it. Nami was no where near in position to help her ADC, you had effectively zoned her out by refusing to leave that bush. You have good vision of river. Use it! Graves is up 1 level but has no potions, he hasn't backed yet. That CS advantage he has is doing nothing for him yet. Never miss free damage when their support is not in position to do anything about it. Wouldn't have been a kill, but would have chunked him to half most likely. You actually DO go stun him soon after, but Nami is now in a position to help instead of in the middle of nowhere.
7:45 - Enemy lane backs, you back. Should have stayed briefly and helped Ezreal push the wave. It was already pushing, might as well shove it hard and make them lose some of it under tower. Then you and Ez could have backed together. As is, you back, Ezreal tries to last hit only and they end up getting there just in time to not miss any of it. That being said, smart move going on Graves when he got back and you saw Nami was not right on his tail. Also, why no sightstone? You had plenty of gold for it. Sightstone and a pink ward probably. It is SO GOOD. Always try to get it ASAP. Free wards. It is basically a gp10 items since you are buying the wards anyways. Not saying only get the sight stone, but you could have easily gotten the stone and a pink ward on that back. Free money. Never pass up free money.
9:25 - Why are you behind your carry? You can see the entire enemy team on the map and you have wards up anyways. Your Ez is not too far up, you are too far behind. Smack **** up. No fear. You can dodge a Nami Q, I have seen you do it. Even if you can't you are Taric. Support is nothing behind the carry.
~10:00 - Master Yi ganking. Why no exhaust Graves? I get not wanting to waste it but you are a little CC light down there and you want that kill to stabilize that lane. Normally you shouldn't need it, but your Ez can't CS well, so you sort of do here. Best to get that easy gold. Instead, you get the kill, but Yi dies because he is greedy. Just forcing him back would have been fine, but that exhaust would have guaranteed the kill. Technically not a wrong decision but when your ADC CSes like a 5 year old, might as well go all out. Plus it protects Master Yi from his clear case of stupid. Wouldn't have needed to dive.
Over all, not exhausting Graves was meh. I get it, it was fine, your Master Yi being tard was the only reason it didn't work out. Exhausting Nami was a waste. You knew her flash was up, she was never going to die there since you went on Graves.
Back to diving, really risky dive on Nami there. Turned out to be the right choice. Probably the necessary choice. But so risky. You knew her Q was almost up, but her ult and exhaust were down. Be careful with plays like that. Good job though.
When you get back to lane (yay a sight stone,) you go to clear that ward. I get the urge, I do. Risky though (as you find out.) You did kill them both, but the time it took you and Ez to run back to tower and then back means you get back to lane at the same time as them. You could have known that by tabbing as soon as you hit base to see when they spawned. You didn't die here, but you took a lot of free damage. Stuff like that without Ez (who was playing with himself back at base) is risky. If their Jungler had been there, you couldn't see him, that would be you dead.
What are you and Nami doing btw? You are both just running around behind your carries. WAY behind your carries. Like, 20 seconds before this gank happens, look at it. Why? You are doing less than nothing back there. I get you are low, at least stand beside your carry. You aren't 1 shot. No fear.
12:15 - Aaaaaand you die due to that missing health. See? Little stuff like taking a few shots in river can add up fast.
I am going to take this time to go in to a little note about the Nami vs Taric matchup. Basically, she has the better CC assuming it hits. She has to aim it though. If you see her use her Q, go in on them. Her CC is down for a while. Punish that missed Q. If it is up and you want to go in, be careful. Stun their carry and just watch for the Q. It will come. You are in melee range of her Carry, so dodging it will be harder than normal (can't walk through the carry after all.) It is risky but doable. Basically, if you are going to risk it by using your CC first, make sure you maximize your odds of dodging it or know you will win the trade no matter what, hard to do vs a Graves. Probably better not to start some ****, or at least don't put yourself in the middle of a bunch of creep and stuff so you can dodge. That gets you killed from this gank too.
Ok, back to the replay. When you come back to lane, you ward river then go to the CS. Meh. You guys could have done double golems first. Your tower is down and Graves is like 90 AD above Ezreal, no reason to go that far up the wave, would have given the Graves time to push (he likes to shotgun the wave.) If you are going to go up that far, due to Ez refusing to come to golems or not push or something, you might want to consider warding wraiths or something. Your tower is gone now as is the mid T1, nothing to stop them from running down that way. Your mid doesn't ward anyways and you can see a lot of their team near top, so you can be pretty sure it is safe to wander up there and lay the ward.
15:30 - You see them go up towards tri, why face check that bush? You are Taric, so it is sort of whatever, but you have wards on you, might as well use them. Not a bad decision per say and this may be one of those things that seems obvious in the replay/hindsight, so whatever. The stun on Nami was....eh. I am assuming you thought Ezreal would kill her, but your Ez doesn't hit for **** right now. Better to save it for the Graves who was either going through the Garen or you. It worked out anyways. Just something to think about. Good exhaust by the way, perfect timing.
16:45 - Tower didn't go down, no big deal. Why are you leaving your Carry though? I know you are low on health, but you are his support. His rock. His guardian. Go back there, stun Lee sin, body block a Q, anything. Might you have died? Maybe, I would bet not, but maybe. They would have been way less likely to go in on that if you had slowed them down with that stun. I can promise he would have gotten out though. That is time he is farming, getting exp getting bigger. Instead he was guaranteed to die. Ez so squishy, you are a BAMF with a hammer and a stun. No fear.
18:22 - Don't run back in to lane that way. I see people do this all the time and I don't get it. You PROBABLY won't die, but if you go around the longer way, I promise you won't die. The tower wasn't going to die right then in there, neither was your teammate by the tower. Be safe.
A little after that last note, don't use your stun to annoy them when they are whacking tower. It wasn't going to do anything to stop them from downing the tower, all it did was mean it was down when they dove a few seconds later. Would have been an easier kill and might have allowed you all to save the turret. Maybe. Probably not. Again, just something to think about.
Total side note, since I just noticed it (I don't know when you bought these, but I just saw them. Maybe you just got them, idk.) Why did you get MR boots? They don't have a lot of magic damage and you are normally not the target of too much CC, so the tenacity is meh. Lucidity boots. More stuns, more heals. This might be a preference thing (you do need some MR so Kat doesn't just melt you) but you guys really need all the CC you can get. Think about it, blah blah blah, you know what I mean. Not wrong maybe, but perhaps not the best option.
22:45 - This is true of ever since you left bottom lane. I don't know how much longer it goes on, but it could have gotten Ezreal killed here so I mention it. More wards. All you have is a basic Sightstone? That is only 2 wards at a time. I know you need items, but your team really needs those wards. You won't win teamfights at this point, not 5v5. You need to catch people alone or in 3v5's and stuff. Wards let you do that. I see you working on what looks like an Aegis though? Good choice. If you had the gold (you don't) a Twin Shadows would have been good here too. That item is great for disengaging and catching people who are in stupid places. Slows so hard. Not relevant in this case but if this game was just a little closer it might have been an option. If you had some more assist gold or something.
28:00 - I don't get why you all are pushing mid. You saw Graves bot, know Kat has to back and can see the other 3 in mid. You have 3 mid, Yi top and Ez near bot. You can't in that 3v3. Hell, I don't know why they waited for Graves. Not to harp on the ward thing more, but you probably could have had a free kill on Graves if you had had some wards there, even just in the river/mid lane bush. Or maybe you could have gotten away. Game likely would have ended there anyways, but maybe you would have been able to hold.
Side note here, don't shatter when retreating. You did it here right before you died (you were dead anyways), but all the times I see a Taric do it when getting shot and running away. That is 30 armor you are losing. Unless you are going to be fighting them and want to shred their armor, might as well keep it for yourself. At that point, you certainly were not going to have your team turn and fight and the damage was negligible, no chance of a kill or even slowing them down really. May as well make them take that extra second to kill you.