I can answer some
1) I don't think it's a problem
2) With that setup, you'll need to run and audio out from the TV to the receiver. You may only get 2.0 sound, it seems most TV's won't pass 5.1 out. There are a couple that do digital out 5.1, but it's rare. The receiver can then do it's best to process that signal to surround so it's better than nothing.
3) Not sure on that receiver
4) No special cable for the sub. Any RCA cable will work, don't spend money on anything fancy.
Actual don't spend a lot on any cables. Check monoprice.com for good cheap cables.