A monthly fee (typically around $5-20/mo) is added on to the payment.

Additionally, how many calls does it typically take you to successfully close a deal using this approach?

Typically those purchasing cash aren't inspecting every home, they're walking it or having their go to GC walk it and already know what they see that may be a concern. 

From what I have seen, the typical remedy is termination of the contract, refund of the EM deposit and all expenses incurred by the buyer during the failed transaction.

From what you've said, it seems like an AITD could work if the cash flow on the equity is solid and better than a typical single-family home.

That's typically because they have a lot of money and experience.

Small shop brokers that have access to multiple programs so that they aren't beholden to one or just a few loan programs will typically get the most competitive product for the borrower. 

When a tenant causes problems, I can remove them six ways from Sunday, typically much faster than the courts could do it.Financial Management & Reporting: It may seem small, but accurate accounting is important and not in the tool box of most investors.Market Knowledge & Rental Rate Optimization: Understanding the market is critical to maximizing returns.

True, but (a) they were typically experienced investors, and (b) today's market includes record prices and high mortgage rates, which is a double whammy. 

The neighborhoods are not upscale but they are desirable so good tenants are typically found quickly.