basically your problem is with his fury, which i think was a great balancer for tryn.
they recently nerfed his heal at early levels cause of how strong it was. it was too strong. got nerfed for it.
his spin got abuff to damage so idk how it's low.
he heals plenty, and saying you have to get rid of your crit chance to do it is silly. you cant be at max power all the time. you have to farm too. dont look so much for getting kills. farm more. it'll build up rage on it's own with each minion kill.
Honestly tryn doesnt need to be touched. frankly i find him ridiculous late game (as any carry should be) being unable to die and have very high base health makes him very formidable. they blow all their cc on you? cool. now your range carry/ap carry can do some damage cause they ARENT being focused. or just build tryn tankier...pd, ie, atmogs. expensive? a little. but you'll have max crit chance really easy, and be tanky enough to not have to use your fury on heal in a team fight.
anyway. tryn doesnt need any kind of buffs at all. you said so in your first post that you're basically just mad you cant faceroll to high ELO :/