Coca-Cola: In answer to your question #1...
1. Yes, 031 tubular track will fit because I have it on a small inner oval of my layout. (It actually measures just a little over 30 inches with all track connected together very snugly). However, you must take into consideration the overhang of your engines and cars in order to avoid derailments. In my situation it's used on an inner oval and I have more than an inch of open space beyond the outside rail.
2. No comment.