Self employed extension; advice needed please;

hi Guys,

I came to uk as a student, switched to HSMP last year. my visa will be expiring in Feb 2010. I am self employed and doing mobiles (sole traders). I did some research and found these important docs for my extension. please have a look and tell me if something is missing.

Tax Registeration Documents with HMRC
Copies of Contracts and invoices(last 6months)
Copies of Contracts and invoices(next 6months)
Business Projections(next 6 months)
Unaudited Business Accounts(last6 months)
Personal Bank Statement
business insurance Documents

Also i have the following queries.

1. Is the business bank account is mandantory for me?
2. What profit should i cliam? Gross or Net.?

Once agian let me mention it that I have a mobile shop and a sole trader

Your help and advice would be greatly appreciated.

Thanks

Gaboon