If $23k is just a “hope and a prayer” then he’s going to have a very hard time producing any CREDIBLE itemized bill.  

If it is way more work and maintenance but cash flowing the same as a smaller unit doesn't make sense, but since you say high maintenance high reward I'm guessing this is one of the best producing properties.  

The C areas that produce the most cash flow are Linden, Whitehall, and Hilltop.

They'll produce a title commitment with the requirements they think are necessary to get you insurable title.

Rental estimates as in what it could possibly produce?

This comes with time and experience but a book that helped me tremendously (not really a sales book, though) was "Boundaries" by Henry Cloud.The most common challenges for RE Agents early relate to generating leads and focusing on income producing activity.I would consider spending 50-75% of your side-hustle time on income generating activities. 

Our main issue is that we are getting exhausted with people who say they're cash buyers and can't produce a POF.

This becomes EQUITY, which can be leveraged 4 to 1 to purchase income producing property.4.

Last year, the city required a bank statement, which was not overly difficult for me to produce; however, this year the city of Chicago required either a homeowners exemption or a state license showing the exact address and unit for the listed AirBnB. 

I would highly recommend you sell and do a 1031 exchange into something that will produce income, like a rental property.