Random Questions for XBOX 360 users

[fabro_s]

Hey guys, I want to buy a 360 by the end of the month but I just want to know some things, hope you can help me.....

Can I create my own soundtrack with my own songs when I play a game?
Can I play Forza or PGR2 on XBOX 360?
Can I use an USB to transfer songs, photos etc, from my computer to my XBOX Hard drive?
What is the differnece between XBOX Live Silver and Gold?
Do I have to pay a monthly fee or do I have to pay something for having XBOX live, or just with my DSL connection I can play online?
Is there a big difference between a normal TV and an HD TV in terms of XBOX 360 graphics?

Well hope you can help me with this one fellas!!

Thanx in advance!!