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. 

Fake financing is allowing you to pay in installments but entirely by the delivery of the property as opposed to paying 100% at the signing of the contract!

No failures and always inspected and approved by local jurisdictionsCompetent installation is a given.

If you have shower doors remove than and install curtains.

The interest is a set percentage that is based on the balance due and is often bundled with the monthly installment of repaying the funding.