Depending on the size of the ADU vs the main property, you would probably be looking at either a "heavy rehab" loan - or a "ground up construction" loan.

What I don't want to do is piss off the squatter enough to where he doesn't leave OR burns the place to the ground. 

The moveable pane needs to be a certain size and the sill cannot be too high off the ground (I believe 42' is pretty common). - number/spacing of electrical outlets.  

The disparity is even more alarming in Worcester, where median income has grown by 19.7 percent, while mortgage payments have surged a staggering 82.9 percent.It’s no surprise that home prices in Worcester have risen, but I didn’t realize the jump was so dramatic.What I’m seeing on the ground is that many of the buyers for multifamily homes (multis) in Worcester are coming from the east—places like Greater Boston.

And most importantly is to work with someone who is "Boot on the Ground".  

A notable sign of progress is that Detroit's population saw a slight uptick in 2023 according to the US Census—the first increase in nearly 70 years, which shows some positive momentum.I've found Detroit to be a good mix of cash flow and potential appreciation, but having a solid team on the ground is absolutely crucial.

The key is understanding the neighborhoods and building a reliable team on the ground, but if you're willing to do the homework, Detroit can be a great market for long-term investment.Feel free to reach out if you want more info on Detroit or need help deciding on an area!

Its gotten to the point where I either need to trim them or just cut them down completely to the ground. 

Mulch or Ground Cover: For the back, you could lay mulch or gravel temporarily.

I believe you can offer her a renewal at $2,000 a month, she won't be able to afford it, and then you have legal grounds to terminate her lease.