This resource covers FEDERAL fair housing law, but I think some states (especially tenant friendly ones) may extend protections further and may even eliminate some of the exemptions.

I edge my odds by not allowing 1) last minute check-ins (must be at least 2 days in advance) 2) No 1 night stays (eliminates partiers) 3) Must have previous good reviews.These will vette 99% of your guests adequately....

Name one product that completely eliminates lead generation costs, and efforts, where the leads chase you instead of you chasing them?

Whether it's buying the first property, remodeling, renting, or selling it slows you down and eliminates impulse decisions. 

Realistically if you have around $18,000-$22,000 liquid per house and its at least drawing even you eliminate the vast majority of issues people run into with over leveraging.

This effectively eliminates all taxable income.

This approach is cost-efficient and eliminates the complexities of dual-state filings.

This eliminates half the risk!

Major drawback was the starter plan did not allow you to customize a lease.Avail had very basic functionality and was missing features such as income verification.They all require a fee for ACH and Credit/Debit, but Inaggo and TurboTenant allow for offline payments such as Venmo, PayPal, and Zelle. 

Adding a lead filter may reduce/eliminate lead content, but they are still going to replace the pipe.