How you screen your clients is and should be a matter entirely in your control. I assume you posted this here because you're looking for some feedback and that's all I mean to provide, you should, of course, ALWAYS do what makes you happy and feel safe.
Blacklists and bad reviews are both very useful things when people behave responsibly, they form a means of warning others of a person's bad behavior. This is known as a good thing. Unfortunately not everyone uses these things in the manner they were intended. When I consider a bad review I often look at details.
For bad reviews to be useful imho it needs to have the following:
1) a source (known users have more value than unknown users)
2) a statement of the offense or problem with reasonable specificity
3) corroboration (one account from one person is less reliable than many accounts from many people)
4) Some methodology to contest the information.
For example if some brand new account put a ROB report up on you here, you'd contest it and any sane moderator would support you. Even if they didn't support you, most users would consider the history of the reviewer for good or ill.
My understanding of blacklist sites is that none of this is true, the sources can be completely anonymous, the statement can be fairly vague, there may be no corroboration, and at least for some places there is no way to contest the information or post an opposing story. With all that in mind I would give it even less weight than a bad review here, but that's me.
If the site you use doesn't have these flaws then I would of course revise my opinion.