Questions about being a property finder for local property investors

I am a property finder based in the UK. I source properties for local property investors in return for a finder’s fee.

Has anyone here done this? Can you offer me a bit of advice? I have some questions:

1) When I source properties and take them to local investors, how do I know the investor will pay me? Do we need some sort of ‘property finder’s agreement’ in writing?

2) Could I outsource the property finding to a team of people working with me?

3) When I find a property, how do I find out it’s value, who owns it, whether it’s repossessed or not, etc?

4) What are the most effective ways to source properties?

Thanks.