The Steering issue is Because Your Tyres loose Grip at Different Rates

When You have a Rubber Tyre they get the same Traction equally distributed. Not the Case With Poly tyres so they always seem to pull one Side..

Even my HPI Sprint 2 does it.. so Dont just think it is a TT-01 problem as it happens to most CHassis..

Tape Your Rims with electrical Tape till the tape is above the edge of the Outer rim by 1 mm..

Really does work wonders and it stops the Saggy tyre problem that comes with using thin ABS.