You can use a tool like AirDNA to get estimates of property performance in your specific market and with your typical size and configuration of home.

I am currently based in Canada and am looking to embark on my real estate investment journey in the United States, specifically focusing on multifamily properties. 

But, you'll need to get with an REI-savvy bookkeeper/firm to help you set it up since it's not an REI-specific software.

Account Closed a PMC has two options to get liability insurance (tenant slip & fall) protection:1) Get added to owner's policy as Additionally Insured (NOT named insured).2) Setup a master commercial policy and add every property they manage to it and then charge those owners the cost of the policy.Otherwise, a PMC CANNOT get liability coverage on a property they have no ownership interest in.So, nothing wrong with their request.

It's hard to give any recommendations without any specific questions/real numbers.

Look up the courses taught by Justin Kivel, specifically the Pro forma modeling course and the real estate financial modeling boot camp.

As a builder/investor myself some of your estimates seemed a little off to me, but those can be very market specific so its hard to say. 

Does anyone have personal experience with specific scrutiny of a logbook during an audit?

So now I'm faced with the potential of loosing EVERYTHING job, house, car, wife...Finally I stopped focusing on what was wrong and focused on the solutions. 

I could be wrong or out of line, but I feel like this is a field where you really need some good expertise/experience to know how to address the variety of crazy situations that will come up.