Visit Visa for friend

I am settled in UK on ILR (NOT British citizen). I want to sponsor a friend to visit me in UK for few weeks. My friend is citizen of an Asian country, and has never visited UK before.

1) We have never met in person (we met online) and talking to each other on phone and emails from 5 years. Is this ok with Home Office if I sponsor someone for visitor visa whom I have never met in person?

2) I live in a rented studio accommodation (not house sharing). Is Home Office ok with this, OR do they want to see at least 2 bedroom property before I can sponsor someone for visitor visa? Is rental accommodation ok OR house ownership in UK is required?

3) As a sponsor, do I need to send my original payslips and bank statements to my friend? I get payslip in electronic form, so can I simply send a printed payslip on A4 paper? Or maybe send scanned copy by email?

4) Do I need to get a letter from my employer stating my salary etc, and send by post to my friend?

5) Is there any minimum amount that should be there in my bank account before I can sponsor?

6) Do I need to fill SU07 form OR write a letter? Can sponsor letter be printed or hand-written?

7) My friend works in decent job in their country, but salaries are much lower there. If I am sponsoring, do my friend still need to show money in own bank account?

8 ) Can I sponsor a friend while I am on ILR, and not British citizen?

Thanks,