A list of 500 people you know nothing about OR Telling the seller or listing broker you have 100 pre-screened and qualified clients that have the ability to purchase that deal size.

For any questions you have, I would use the search function at the top right of your screen.

However even with a good screening process set up you just never know.

Is it legal to post a sing stating that you will only rent your room in your house to a female?

Sounds like you did everything you could do to screen the tenant but these things will happen in this business.Just roll with the punches and move forward.

I see you signed up as a "wholesaler" that says a lot.Might be time to get out from behind a computer screen and meet real people in public, talk to people in RE who are out there in your community.

The people who are uncomfortable living next to the owner (for whatever reason) will self-screen themselves out.

Eric Drenckhahn wrote several great blog articles on screening tenants.

In most of my properties there is an Austin feel - we use a lot of hand made steel planters and black rock gravel in the landscaping, metal roofs, and screened in porches. 

Historically I have always screened tenants one at a time (mainly because the applications tend to come in every day or two) and have chosen the first qualified.