you should go for the crash team rac-
A CTR style boosting mechanism could be interesting. If you fall from high enough you get a speed boost. In CTR it was essential to use this mechanic as often as humanly possible for the better ranking times. It was basically the core of the game.
yes.
also make a crash team racing kart;

because of its simplicity and fantastic style.
for powerups, you're going to need the invincibility/GET THE forget OUT OF MY WAY forgetERS! power up, thats like the starman.