If you download a corrupt file to the phone and it screws the phone up, verizon is prob going to ask you what you were doing and they may fix it or may not. I've heard both sides of the story. Many times you'll just be able to remove the file without any problems. Better yet, don't put any crappy files on the phone to begin with.
Themes = no. The only verizon phones you can do this with are
pda style (Q, Treo)
Linear Mode
