First off, I appreciate the approach being taken to change TT. Working with the playerbase sounds like a good way to go, and I dearly hope some of the audience's advice is actually taken. Here is some of my imput, as an avid 3's (pretty much exclusive) player. Just put point form things, with a description of what I think. Hope it helps!
Buff in Middle of the map - I haven't done the testing, but if its anything like dominion please no. TT was nice because it had the same style as SR, but on a much smaller map. IMO, adding 'new' mechanics (take buffs, speed rings, bells and whistles) will ruin it.
Jungle - Definately needs to be revamped, as pointed out. Putting the focus on the middle will definately make things interesting and more face paced, which is what TT is all about. Being able to kill the buffs at earlier levels would be nice, which would open up more champs to jungle.
Meta - Please don't turn this into SR. The funnest thing about TT is there is no set meta. You can mix up combo's of AP / AD, ranged and melee and make it work. Im off to 5v5 the second I join a game and have to fill a certain roll. Meta's cause rage, someone picks something that isn't what "should" be and everyone gets mad before the game even starts. Keep the open variety of choosing champs.
Champion Pick - I like what has been proposed to open up more champs / make them viable. Has always been a problem on TT.
Ranked - Ranked solo pick would be beautifull. I hear this splits the group in half, but I have no qualms waiting 2 min instead of 1. If not, at least put in a draft normals.
New Items - Im not sure i read it right, but again, I think the same items as SR worked just fine.
Ultimately, I fear this is just Riots way of making a new map, and getting rid of its much hated child, TT. Please don't change this into another dominion. TT is fun because its a mini SR with lots more action, but not so much as Dominion. IMO its the perfect balance, and I hope it stays that way. Good luck with the changes!