Bans on Forza 4 restrict storefront, clubs, online matchmaking, and auction house. You may only play campaign and custom/player-made games. Those two things, I only play anyway. Being banned is not a big deal, especially having a large amount of cr and unicorn cars, there really is no need for storefront or the auction house. If you are worried to modify your save, I can and do edit your stats to reflect the possibility of what is modded. It will not promise safety from a ban, but will help immensely in the chances of getting banned. You can find my shop on here in the forum section. Have ny more questions, feel free to ask.
-Tango