If the bodywork is good. Black is the least forgiving color when it comes to bodywork, it will show every tiny imperfection. Also metallics are harder to spray so if it is done right it will look great, but you definitely can go wrong with metallic black.
Filler should be less than 1/8 in thick. Filler absorbs moisture, moisture = rust.
Those conditions make it not suitable for filling large areas. The correct way is weld in new metal and then use filler to blend if needed. Fiberglass is also another acceptable way to shave the markers and tail.
I had major starting issues, then I rebuilt my SU's (ZT Kit) and now it starts very well. So, if you haven't thought of that option, you should consider it.
just put all the poly bushings in and go to a parts store and get ball joints and tie rod ends.
besides springs and shocks thats basically the entire suspension
Check out the Tech tips section of atlanticz.ca they have some sweet writeups (with pics)
brakes and wheel bearings are also something you could do to "freshen up" the car
So he was staying the night at his gf's house with out a garage, huh? The real question is why weren't doing it in the GTR. Hell, tons of people have houses and beds, not everybody has a supercar!