Konabear

I am new to this forum but have been reading with much interest. I have a 1993 FD and I am the first and only owner. I have installed Koni shocks, I have new Michelin XGT-Z4 tires (225 50's in the front and 245 50s in the back) all the way around. I just had a new motor, turbos and had the trans rebuilt. Now, I have a couple of questions:

1. My car seems to feel a bit loose in the front, mostly when accelerating hard. It seems to handle ok but just feels a bit loose. I know nothing is broken it just doesn't feel right. Any ideas? Strut bar, bushings?

2. When the new motor was put in (by the dealer) they removed the pre-cat, cat and I have a greddy exhaust. I have replaced the parts with Pettit pipes. Do I need to worry about boost creep? Pettit sent along some type of restricter (basically a new jet) but I am still worried about my new motor. Does everyone suggest the Pettit AST other than replacement?

Any info those more knowledgeable can offer will be greatly appreciated.