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?

LLC/ Corporation documentation (Must be a US based corporation or LLC) Most lenders may require a minimum credit score of 650 for this program if the borrower has US credit. 

I bought a condo with the intentions of running an Airbnb and it was quickly shut down however I ended up turning it into a corporate rental.

Maybe not anymore, for now: https://natlawreview.com/article/texas-federal-court-issues-nationwide-injunction-against-enforcement-corporate

However the owner comes from corporate world and they started out doing deep dives into markets and moving Hedgefund type portfolios between large investors.. they then decided to offer there service to smaller turnkey type and one offs..

If you're not sure about your contractual rights and obligations, seek legal counsel.  

I am reaching out to inquire about the subletting policy for corporate leasing opportunities I am interested in exploring the potential for flexible rental arrangements within your properties.Could you please provide me with information regarding your corporate leasing policy and whether it allows for subletting or alternative rental arrangements?

You will be dealing with high school kids who are your employees...I know, there will be a manager, but a manager can only go so far...Plus corporate can come and make you change this or that, you will be obligated to comply.Seems like a headache to me even more than with rentalsSo Ive decided when I retire, I want to enjoy my life, not to deal with a headache from a restaurant

It seems like a reasonable approach, but as you say, we'll have to wait to see what the final version of the law (if it indeed becomes a law) looks like, then figure out if a European corporation with third country investors is a reasonable solution. 

My markup is always lower than the original lender's because I don't spend money advertising during the Super Bowl, my president doesn't have a corporate jet, and we don't have layers of management we need to pay.