The only caution that I would give you is to modulate your mailers. 

I had to bring my car battery home with me at night lest it be stolen.  

I would recommend bringing some extra batteries in case one of the smoke detectors dies before he shows up. 

A concern would be that the batteries would be dead forcing my tenants to be locked out. 

Other than that, soap, some batteries AA & AAA & 9v, notepad pen dishwasher tabs a smelly candle dog treats poop bags TP paper towel a colouring book/ crayons if they have a kid some Lysol wipes and such. $20 gift certificate for pizza joint hand written “moving sucks, this may help”.

Get the smoke detectors with 10 year batteries, put one in every bedroom, every hallway, and everywhere but the kitchen. 

The battery gives up about halfway through the night.I don't think $14 is too much to pay for the security of lights.

This means they pay for things like light bulbs, batteries for smoke detectors, etc.

Single Family Homes can be buil in modules and the modules stacked for 2-3 story homes.

-Change smoke and carbon monoxide detector batteries at move-in.