Check out the thread lower down
In short, yes you need front camber to dail out understear and more than just TT arms, they alsonadd track which has an impact
Tyre wear should not be a major issue at 2 degrees (stock cars have over 1.5 at the back)
If they are on the car they will be over 1.5 degrees, possibly nearer 2 with lowered ride height. I assume you have set the geometry following fitment ?