The solar system adds no value to my property for rental purposes, and I may even be ripping up the roof & replacing it in the new year.Beyond sending a nasty letter through my attorney via certified mail, demanding the company come pick up their equipment, am I required to take any further action or fulfill any obligations regarding these contracts?

Adding paint and replacing flooring is not going to add much value in the typical case.  

Let’s unpack your ROI question in a way that reflects the reality of your financing setup.When calculating ROI with multiple loans, you’ll want to include all financing components in your cash flow analysis.

The bathroom and kitchen were replaced.

But most of these bridge loans have future funding components where the lender will fund renovation work as the work is completed and add that to the loan balance. 

I require tenants to replace consumables like refrigerator filters or HVAC filters.

I mean you technically require a permit to replace an outlet or sink faucet hahaha

You technically do not have to replace the mortgage. 

I assumed some would need replaced, which would be okay, but I would hate to see it all trashed.I guess in that vein though, I hear that a lot about LTRs -- the horror stories -- and we have been blessed with amazing tenants (generally) so I was thinking it would be along the same line where it would be something where you would want to charge high-end and screen intensely to try to get a tenant that just is transitioning and can benefit from the furnishings.I know that could still happen though, even with all the precautions you can take, so it's something good to consider! 

•Systems: Servicing the HVAC system, replacing the water heater, and updating the electrical panel.The renovation was completed in 13 weeks and totaled approximately $35,600.