1 - in electric touring, foams are generally for carpet, rubber is used for asphalt and sometimes carpet as well.
5 - cuz they get REALLY hot
6 - being geared too tall, other things as well.
11 - I dont own either of those cars, but they are very high end tourers and both very highly regarded. The AE would probably be easier to get parts for. There are huge threads here for both, check em out. There are lots of other options for touring cars that can be competitive, however, so check your LHS and see what they have and recommend...you dont HAVE to have a tc5 or xray to be competitive, neccesarily.
12 - I always wonder that too, but I think its because it is a proven winner, and that it conforms to the rules for the class...and it looks cool