I was looking to rent a little while back in the area with all of the Mount streets and the cheapest house was $2700, although it was renovated already but still a basic house with 3 bedrooms, 2 baths and a small yard. 

I would not recommend any hanging light fixtures, replace all with ceiling mounted light fixtures...the only exceptions are ceiling fans.

It avoids the problem of repairs mounting up in excess of the deposit, and is also "trains" the tenant to take better care  of the property.

First get your engineer on it, then:*Mount your laser level in a spot where hopefully it will be visible in at least a few spots (duct work in the way)*One ton bottle jacks to lift to exact spot quick (Expect sheetrock repair upstairs).

I will look into putting in electric heaters, putting in propane wall mounts, and getting separate boilers and oil tanks for each of the units.

There are extension cords being used in a permanent fashion running from the basement and through the house to some other rooms to provide more electricity in those rooms, and there are mounted power strips to provide these extension cords with power.

I think it takes a lot to "move a toilet" however perhaps it was an older device with rusted mounting bolts? 

The mounted stainless rod, if damaged at all, is tenant damage and I charge repairs to them. 

That is a vented usually wall mounted heater.

Residential and commercial landlord tenant laws are night and day different and not even close to being the same.Landlords in commercial mount responses to commercial tenants.