You need to check local laws because there are some nuances on controling thermostats and utility billing depending on the state.

When I entered the office I was greeted by the controlled chaos.

The only option with some degree of control and safety is Short Term Rental. 

Many of these homes are now built with 2x6 walls, not to mention great precision.

You are correct - the terms can be great and with the exception of the monthly interest payments, you control the payback schedule.You can add a business or personal line of credit (LOC) as well if you can get one.

We are not in rent control zone.

Using other peoples money is a great way to keep you honest on the project as well keep the project out of your pocket.I thought funding my own would give me control but what it really did was hogtie my leverage and made me emotional in my decisions.There may come a time when funding everything makes sense, but even if you do a few flips with HML, you will understand the process, have a foot in the door and be positioned to act on ANY opportunity when it comes along.And having a bunch of your own employees just means that they are looking to you or leaving you if the work slows down. 

And about the HVAC systems, I think I want the mini-split so they can control their own climate.

Really looking to upgrade to battery powered access control to be more efficient and cut costs during turnovers.

Obviously you can't have complete control on these but you can get a gauge when first speaking with the person.