You can't use a PO Box for a business entity.

In my experience, the good ones are expensive, typically require a subscription, and sometimes they even do a physical inspection of your premises to verify it is a legitimate person / business in US.

Airbnb is not our business. 

Mid-term is more likely to work in any market than STR, but I think you would be surprised at how well an STR could do if there are no other options like that in the area (think people's parents or friends coming in for the week(end)).I've seen a lot of people grimacing at the net-negative house hack (it's just a product of rates and low inventory in a lot of markets) and this is one option to try to recoup some of that loss.

I know some municipalities allow the property owner to obtain permits but  that in itself is a huge issue in many areas and secondarily insurance is critical in this business.

The PM business is not an easy business and most have fair fees for the work that's required.  

It would be nice if you gave them more than that, because it takes a lot of effort to move a business (online marketing, business cards, etc.).

I would look up NARPM and start with them..Below are some questions I would think would be a good starting point for you to see who really treats their company like a business or a hobby.

Any other sympathy is unfortunately just Poor Business Practice.  

Most of us have passions that will never be followed, amazing businesses or ideas that will never be pursued… unless we can solve the Cash-Flow Freedom Equation, which ultimately leads to Time-Freedom.