It is suggested that  "Small" landlords use a collection agency, who will report the non-paying tenants to the credit bureaus.   

Marcus,If you want more exposure you can list it on the MLS, and you will have to pay a fee to the agent that brings you the tenant then you will have to do a credit check and background check yourself for each applicant however for my clients I prefer to list it on Zillow rentals only, because I can manage the applications directly from there and the prospective tenant only pays $35 application fee once and can apply for different properties with the same application fee.

If they pay everything cash why do they have a low credit score?

To pay for the renovation, we did a cash out refinance.

All it's looking for at that point is total liquidity, credit score, factors on the property itself.1040's, pay stubs, Debt to Income ratios and things like that aren't a factor here.

Short answer - tenant pays.Long answer - landlord pays because tenant has no money to pay that's why they are on section 8.

I have insurance right now but I am paying upwards of $600 per door! 

He is paying a rate higher than a bank but lower than hard money and he can refinance after his equity has increased. 

Then, if you have any debt, start paying it off quickly.

This is about to bite us though as commercial loans only lock for 5 years - so our 4% commercial loan will reset in the next year and probably increase to the 6% range if we don’t pay it off before then.