not directly. You'd have to convert a lot of textures over to 06 fsh files, mainly jerseys, but possibly other files (i forgot which things are and are not compatible)
It might be. It's easy enough to test yourself, just place the menu art files from TUP 11 in your sgsm folder and fire up the game. If the game crashes or you encounter any other problems, just remove those files from your sgsm folder.
Most of the files are incompatible, I'm pretty sure of it. There will be incompabilities with the art too but as Andrew said, backup and test for yourself.