[Chris W]

what type of box do you have now?

Which software are you using? (new virgin black software?)

It sounds like a return path problem if you can't get anything red button.

In answer to your questions:
1) sounds like a return path issue- see questions above for more diagnostics
2) You can't on the virgin software i am afraid. The best you can do is set your favourites, then open the mini guide and press red to browse this list. Kinda handy.
3) this is a little basic on virgin, and subject to the red button working. Which extra channels are you referring to though?
4) I'm not sure about size M, but i have loads of +1s, Challenge, Discovery, UK Gold, Bravo, Trouble to name but a few...
5) See above (possible return path problems)