Retain a cash reserve to cover vacancies or downturns, and align with your long-term goals by consulting a financial advisor.

I feel better now, but perhaps I should start looking for a lawyer who can help on the matter of the tenant taking in her mother without my permission and they having walled in the deck with heavy curtains, which impedes air circulation, etc.  

Moving walls usually requires figuring out what is or isn't load bearing and likely putting a large and usually expensive header.

Retain a lawyer and sue for damages? 

Real estate's "gross rent multiplier" is Wall Street's "sales to revenue",  "cap rate" is roughly "P/E ratio".When evaluating markets and investments I tend to start with GRM (or lazily the 1% rule), then attempt to return a cap rate based on assumptions about costs, then I work my way to multiple years of projections (assumptions about inflation, amortization, tax benefits, etc), and if I am partnering with one of my smart friends I have to pull up an IRR (internal rate of return).I also look at regional employment levels, median income to rent ratio in the zip code etc. 

Quote from @Jaron Walling: @Elizabeth Leb Every dollar of that $20k needs a purpose.

I rebuilt a house in the area a decade or so ago that had cracks in the walls that I later discovered had a 6 foot diameter bee hive in it.

If lenders reject a HELOC due to lack of W2 income, explore DSCR loans, private lenders, or partnerships to fund new investments while retaining your current property.

Common fees will include a set-up fee, a leasing fee for each turnover or a lease renewal fee, marking up maintenance, retaining late fees, and more.

Laundry room wall painted black is odd.