It seems to me that you've thought about this Service idea through.
And i totally agree. People who want to open up a service should almost go through a 'background check' as described in the original post.
Being around for any length of time doesn't have any threshold on trustworthiness.
As you can see, I've been here for a small amount of time and I just refuse to scam anyone. I don't understand how being on this site for any length of time would make you trusted in any way.