Giraffiti: Vandalism spray-painted very, very high. 8.

If the coils get dirty, which they seem to even with cleaning the filters regularly, you can spray them with Coil Cleaner. 

For example if a tenant pours sand down each drain trap, or spray paints the walls, etc... would these activities warrant criminal vandalism or civil lawsuit grounds for the cost of repairs/lost rental income? 

across the front of it in red spray paint!

Pest control has sprayed everything while the walls are opened up to hopefully prevent problems in the future. 

Sprayed on asbestos insulation is highly friable.

I know you authorized only $150 (which was twice over the prevailing amount) but I didn't want to bother you.There are too many cockroaches even after you gassed and spray them.

For example, we change the furnace filters in every unit because otherwise it won't get done and we want to get as much life out of those furnaces as possible.We also regularly pay for a guy to come out and spray for bugs. 

Stickers with the door numbers may come off after several weeks of daily rain, spray painting?

Pepper spray, stun guns, tasers, knives, handguns, hard objects for striking (kubotons or other things that be put on a key ring) are legal to possess, carry, and use in some areas and not in others.