Will driving with my TCS off do anything like Better HP, or more MPG?

 

no difference in HP
and probably less MPG as you will be spinning your wheels at every stop light lol

 

With my TCS on, I'll occasionally get into the situation when going WOT the car will bog down and take a few seconds to wind up. And even then the windup will be slow and you'll get trounced by a VW beetle. Keep TCS off except in wet and slippery conditions. You'll have more fun.