The only issue we did have was unwanted people living there who were not on the lease.I am not sure on the specifics in your state as to evicting these people in case that you need to. 

Less inventory= better chance the seller will tell you to pound sand if you try any of the above.

I wouldn't even return the cleaning fee to be honest, I'd politely, or maybe not so politely, tell her to go pound sand..Rain.

An owner brings in a 20-pound dog for a rabies vaccine.

Lots of them try, but you can just tell them to pound sand. 

Look at it as an ounce of pain or a pound of regret..you're not going to win every offer and every prospect isn't going to check out.

I'm more an ounce of prevention is worth a pound of cure kind of gal. 

I worry it may be more likely to attract unwanted attention than it would be to attract future guests.

This may attract unwanted attention though, I would make sure the property is well secured regardless. 

I recommend you read some books about how to manage properties well, use a strong contract, know that contract inside/out, know your state law inside/out, build policies and procedures to catch and stop problems quickly, know how to screen and select good applicants, etc.An ounce of prevention is worth a pound of cure.