You should certainly speak with a real estate attorney and then double check their solution with a CPA. 

What you are asking is the same question that everyone has when you start in real estate investment.The solution for financing is what Jay mentioned.I think you need a real estate agent that can help you here.

Based on our conservative and thorough analysis, we have identified this as the most accretive solution for the investment.

And then the solution was to block my unit off as owner-booked, or to “resign the listing.”

Bait and put exterior traps outside,  the black plastic ones bait goes inside.Mice will crawl right up the side of a house, or drop onto house from tree limbs so make sure tree limbs are kept clear.

This can be a more cost-effective solution than having separate water heaters for each apartment.

Yes, there is a solution, but it isn't a quick post.

Try to find a solution any future issues like this.. 

It is not a solution for long term.

Thanks I would look to AirDNA for this - they have long had pretty good (guidance, not perfect) rentalizer solutions for projecting revenue, but have recently added good info on expected expenses and the property managers in the area (for at the very least coming up with expected operating / management costs) etc