**Maintenance**: Be prepared for a bit more wear and tear compared to market-rate rentals.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

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

I understand I cannot legally require them to respond, unless the notice specifically requires it, like for instance, a notice of entry, but it's making it difficult to manage the property, and I'm not sure how to proceed.

I actually like them because the homeowners' association (HOA) usually covers most of the insurance, and there is very little maintenance required.

Requiring occupant to have renters insurance is another possibility for extra protection.

Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

FHA loans typically require the property to be a primary residence for at least one year, so he should confirm compliance with his lender.Once rented, he can deduct expenses like mortgage interest, property taxes, maintenance, and depreciation starting from the date it's available for rent.

I think it would require a major asset heavy backer to provide the confidence the investing public needs to scale to profitability.  

Vacancy, maintenance/cap ex, PM, Misc.