Where might Taric fit in dominion? A bot laner? Some sort of defensive pick? What might one build on him? I heard attack speed and ap looks really nice on paper, but is it even playable?

Taric can actually be built a couple different ways. You can play around with the builds and see what play style works best for you. He isnt really a bot laner, havent had much luck with that.
I really enjoy playing him as, ap. Go mercs, nashors, malady, aegis, other sustain items or as items depending on how much damage enemy team is doing. This build is fun because your Q comes up so frequently and you get tons of mana back.
Another way to build is burst ap. Build mercs, then ap items such as lich bane and rylais for sustain, even roa can be useful for him. Ive seen this played fairly well but havent personally tried this build.
The most popular taric build is tank. Items like mercs, odyns, aegis, randuins, frozen heart. Again i have not tried this build because tanking is kind of boring to me. But the important thing with each of these builds is to try to max out on cdr so you can spam his abilities.

Gl and hf :)

I've always built him aura/cdr for support and he's the biggest beast ever. The Nashor's Tooth has been a prominent suggestion which gives me a goooood feeling about it. Think I'll start throwing things together then

I typically build Soul Shroud, Mercury Treads, and then Frozen Heart as his core. This puts you around max CDR with masteries, so guess what time it is? 6 second CD Dazzle time. After that, I try and complete Trinity Force. Taric has super high base attack damage, frequent use of his skills, and his heal comes off CD faster the more you attack something. Trinity Force is just too good to pass up. Usually the match is over, but I complete the build with Wit's End and Hextech Gunblade.

The best thing about Taric is that he completely counters all the AD bruisers you see running around in Dominion. A stun, ungodly amounts of armor, an armor debuff, and a massive heal makes 1v1ing Taric near impossible.

Black cleaver, starks fervor is surprisingly effective. Combined with a good shatter, that's up to 95 armor removed. Toss in your ult's 70 AD on top of that, as well, when it's up.

Thing to remember about taric oging ad dps, is he is very kite-able. And black cleaver + starks is expensive. Most tarics who go ad dps get kited hard.

Thing to remember about going burst AP, he doesn't put out that much damage burst, and his burst has a fairly decent cooldown.

He isn't bad, but he is outclassed by lots of other stun champs

taric stuns, by hte time he reaches you you are unstunned. You use any disable on him, can move out of the way.

Have personally kited him with Ez, Vayne, Kog, Talon, Kass, Leblanc, Urgot (stayed out of stun range), pantheon (dealing more damage while taking less).

Thing to remember about kiting. It doesn't mean take 0 damage, it means avoid staying melee for a long time. Easy enough to do. Take less damage while still dealing damage.

Taric can be kited by a large number of champs. Add a solid disruption and he will never put the damage down

Building Taric straight tank is deceptively good; his armor shred combined with his ultimate give you an incredible fighting presence. Not the best pick in the world, but not useless by far. He is best used to defend a point.

i went crit taric and mopped up lite most ad chars. something is wrong with dom.