What is he charging for the materials?

If there is one thing I have learned, is nobody is going to charge you a fee to learn to get rich lol.

That amount is baked into the rent you charge.

How many people hours at what pay, plus cost of buying lists, plus skip tracing, plus phone/texting charges, plus office overhead and so on and so on.Noobs think texting is cheap to free ;-) 

The agents are charged for this service no matter what so it's difficult for the agent to service from a time and financial perspective.

I can make the down payments in the smaller market on cash-flowing deals, but these bigger markets require 40-70k to make a deal the conventional way, and I just don't have that to invest.

I don't think those are bad things and sometimes the personal decision for your ideal life outweighs the "conventional hold forever" decision.You have options, that's the best place you can be.

If not, I'm guessing it would be treated as a traditional rental loan, either conventional or DSCR, using market rents rather than the rent in the lease agreement.

You can theoretically have a higher rate from one lender with lower origination fees and total finance charges may come in lower.  

If you don't specify a charge in your listing, you can't collect it.