what is shared across multiple accounts on a Xbox 360, and what isn't

[Lionel75]

I just got a new xbox 360 after mine broke last year. I decided to make a new account to start fresh, because some of my data on my previous account was wrong. I had that account for multiple years, so I have some bought themes and received themes through pre-orders. Same thing with gamerpics. They can't be used by my other account though. Is there a fix around this?

My main question though, exactly what is shared across multiple accounts on a Xbox 360, and what isn't? It's kinda confusing, and I can't find any topic on Xbox.com's support pages.