They substantially damaged many items (destroyed outdoor sectional, left $700 vacuum OUTSIDE in the rain, destroyed marble countertops, scratched wood floors, and various other items including leaving various personal items randomly throughout the home (including sex toys) that I had to dispose of.Fully documented items using an Excel spreadsheet.  

(Why should it matter they are all equally qualified and you dont discriminate)Now applicant 2 & 3 decide you didnt pick them because of their (race, sex, age, disability, religion, etc) upon being investigated they have a legitimate claim...If you go with what most are saying about 1 at a time, then you truly are choosing the first best applicant.

You state he's been a model tenant for three years but perhaps the mix of housemates age and sex is the real problem, this is why I mentioned how you structured the leases and if you are matching up the tenants. 

She helped me scan through the MLS and pick out the places that were under market value, had decent rents (met the 1% rule), and were in good neighborhoods (determined by school rating).FYI I'm not sure you're allowed to discriminate based on sex (females only).

The sex offender thing always gets me too, girl 17, bot 18, dad finds out, nails boy, later boy marries girl, tells dad to take a flying leap.

What if the other guy dies, gets a divorce, rents his half to a sex offender You can't control any of these scenarios.What would be your exit strategy?

I also wanted to search for apartments by sex of the owner (a female might be more likely to stay in a female owned listing I would think), etc-- but also, no way to search for that.

And considering you cannot control pride of ownership in totality since you're in a neighborhood reduced additional value IMHO (e.g. you cannot evict the neighbor with two cars on cinderblocks, three sex offenders living there, and 8 pit bulls tied up to the oak tree).

Assuming Bill Gates is an excellent lover (I know, gross thought) and he and his wife make love for 15 minutes, using this logic, every time he had sex it would have cost him $270,000.  

Their color and sex has nothing to do with whether they are good or bad, so you shouldn't bother mentioning it.You failed in your screening.