Steps I was thinking of following:1) Get electrical up to code since its all 2 prong outlets and the panel is way outdated.2) painting of the whole house3) Demo kitchen and bathroom4) Renovate kitchen/bathroom5) install new floors6) input new appliances7) input new light fixtures8) etc.

My Renter of 2 years wants to install a TV mount for their flat screen over the fireplace.

What you are describing is similar to telling the power ball winner not to take his 50 million lump sum, and spread it out in installments so he can get more.

What type of business do you plan to install? 

This is to avoid things disappearing during construction, getting damaged and arriving just in time to be installed by contractors if need be.

Whether it is profitable depends on the cost of electricity from your utility; your local/state incentives and net metering policies; and the cost to install the solar panels.A pretty easy and quick way to run ROI on a solar system is to use this tool put out by Google: https://sunroof.withgoogle.com/If you look at my post history, I'm in a similar situation and I will be going forward with solar when I do my roof.

Also, full disclosure - I have utilized creative financing & transaction structures (installment sale transactions, had the seller take back 2nd position notes, baked brokerage fees into the agrement of sale  in off market transactions to name a few), so I am not opposed to it, but they were utilized in very unique and circumstantial land entitlement transactions. 

For the existing home: I have to install a separate heater that is thermostatically controlled from inside the apartment - I found a nifty little unit that will do the trick for under $300.

I will be installing these myself.

I have heard of thermostats that you can install that have a minimum temperature setting (say, 50 or 55 degrees F) to automatically turn on the heat even if the tenant doesn't have the heater on, and we'd like to put those in to prevent frozen pipes.