Change smoke detector batteries, new thermostat battery, replace furnace filter, look under all sinks, drain water heater once every year, look in the attic.

What does your state/county say about hability standards and temperature because a nest thermostat may help you all pay utilities if they are in your name, don't go below or under the legal limit and don't risk your pipes. 

Each room has its own thermostat and there is plenty of parking and land around the building.Possibilities include medical offices, storage facilities, convert the building into apartments, etc etc etc.The possibilities really are endless. 

While Rhode Island Energy will subsidize smaller improvements (e.g. a new Google Nest Thermostat is $75 off), RI and RISE can either directly subsidize or provide you with the info to subsidize new windows, solar, blow-in insulation and more.

I would definitely install a smart thermostat asap!

If you can't self manage (which everyone thinks is easy - but it's a LOT of work so depends on your available time to devote to answering basic questions over and over, calling 3 cleaners to replace the one that called out for the 5th time in season, calling an A/C company because your guest turned the thermostat down to 65 in 100 degree weather, etc.) then either go with iTrip if they have a strong franchise in your market or a mid-size local company with a good reputation.

Upgrade to Smart ThermostatsTech-Savvy Improvement: - Install a programmable or smart thermostat

Water Heater Not Producing Hot Water   Quick Fix:     - Check the thermostat settings

I just ensure my first floor tenants keep the thermostat at 68 degrees from 6am to 11pm and 65 degrees 11pm to 6am (NJ Law). 

First, i would not furnish the places, it will probably get trashed, let them get there own furnishings and make sure that the lease says they must remove them from the property when they leave. i would have them pay for utilities, to an extent - have them pay for electric, supply the heat but give them an allowance for certain amount of months ( especially if you have older furnaces and they run on oil heat ) if they go over then you charge them for it. i converted mine to gas with new furnaces, i include heat in mine, but i control the thermostat ( online, thermostat is locked at the house ). i also provide water / sewer and free internet.