Would love some insight and if anyone is interested in working on this one with me, could potentially work out as a win-win.  

All the probate issues are up to the trustee to work out.

Thank you @Lawrence ZhouWill start looking into those areas.If things work out perhaps we can help each other out with challenges and questions down the road.I am in construction management (electrical construction specifically).If there is anything that I could help you figure out let me know.

Let's also assume the room is always genuinely locked and I'll have a reasonable way to argue this, e.g. something beyond "it should have been locked".My thoughts:1) It's a locked door, literally no one will know there's a gym on the other side2) Worst case is that someone broke in, worked out or claimed to work out, and filed a lawsuit saying they used the home gym and injured themselfIf I have evidence the person broke into the room (e.g. video from the inside of them breaking the door/lock), would I still be realistically liable?

If you can eliminate your PMI and get a solid rent rate, and you already have the financial capacity to take on another deal, this seems like the obvious choice.

Open houses have limited capacity and people are required to wear masks and asked not to touch anything.

Though, if there's not I'm not sure how that would work out in the long run. 

In my experience, an amicable mutual termination of a lease can often work out in the landlord's favor. 

Do you have time/capacity to find deals, negotiate deals, manage day to day or do you need to be hands off?

That'll take the guess work out of it when you receive applications and make decisions like this so much easier because applicants will either meet your criteria or they won't.