There is usually extra charges on closing to pay for that service… but it is minimal.All the best!

Some try to charge an up front fee.

Generally they are not rolled into the loan, and it's more the level of fees (say the percentage) they charge rather than any "junk" fees or costs.

Freddie Mac only offers financing for single properties they do not offer 'Portfolio loans" meaning bundle them all into one loan.

Is saving the fee a PM charges worth the potential thousands in cost and headaches?

The builder had a given us the paved yard, Granite kitchen top, washer and dryer at added value with no charge.

If the agent is doing the marketing, finding the potential buyers and possibly working with other agents to help you secure a deal then I would still charge 2.5% for my listing services and 2.5% to any buyer's agent. 

I think hard money lender to take this risk cannot legally charge appropriately which means the law is working against you (the law meant to protect owner occupied owners from unfair loans).I agree with @Jay Hinrichs that your best option likely is to sell on the mls.  

Is it possible to re-finance these separate properties as a group in a single loan?

We are currently charging $1300/unit/month  and expecting to be charging the same this coming year.