GTA has so many possibility's!
Its a game where they could make anything to be honest.
I think you should start off in the middle say, giving you choice to up or down.
Become a wealthy man, lots of houses, cars, etc. or poor, bad car, house...
And have it really realistic, because face it, we play these games to a ) escape life! & b ) to do things that in real life we would never do or cant do. So if it was realistic then it would feel more like real life and would be more fun.