I also don't want to be housing a convicted rapist, thief, drug dealer, etc.

We just remodeled and have an alarm system, big lot, so the price seems fair to market.The neighbor had been living in her grandmother's winter home, paying rent, and thought she would be there for another year.

I would recommend swapping out smoke and CO alarms with the newer 10-year sealed ones.

I was charged a ridiculous $200 to replace a fire alarm battery which I did myself before when I lived in the unit and the battery was $5 from a store.

Might just consider a decent alarm system.

(We need to do a safety inspection regarding the kitchen fire extinguisher and the smoke and c/o alarms).Take photos during the inspections, and ask and check about leaks, outlets, and switches.

Gutter cleaning, furnance checks fire extinguishers, smoke alarms.

If they don't stop you can buy an Airguard or some other brand of marijuana detector alarm and have it installed in their unit. 

You can read alot of books and listen to a bankers opinion all day but what help are they going to be when you enter a unit for a filter change and smoke alarm battery check and you discover things like tenant has moved in a roommate, are those bedbugs on the wall, why is there a pet tiger in the bedroom...etc...You will need a voice to call to say what in the hell do I do?

or door Alarms?