However, since the value of a commercial property is almost solely based on the income of the property, investors and bankers alike have grown to love balloon payments and rate resets.

Absolutely fair points and fair assessment of both Nimby's and Yimby's typically based on how they will be PERSONALLY affected. 

Based off my assessment of your air bnb listing overall it needs updates , it looks outdated.

Does anyone have good experience with cold callers and where they're based out of?

The mechanics of the deal are not too complicated, although as others have noted you can't advertise the property and then exclude people based on protected class including gender and family status....at least not legally. 

My realtor commissions get paid to my LLC which is an S-Corp so I pay myself a salary based on the total of the realtor fees and other flips I do throughout the year.

Based on my experience with hoarders - Leave it alone.Unless they are causing damage you really don't want to spend your energy chasing that.

Here are some recommendations based on the limited information you posted:Yes, I would get the chimney flue installed.

The accountant that we had last time is based in Chicago, specializes in real estate and is a good one.

I'll be moving to McGuire AFB in New Jersey and am looking for my first property within an hour of the base.