from the little I know and its only because i have brokered 50  100 unit apartments the buyers are quite sophisticated and have a lot of cash and have their lenders lined up.. 

I use brokers but they've been a bit of a disappointment lately.

I have NEVER seen a pro forma statement put together by a seller or broker that 1.

However if you are getting the buyer yourself and need an agent to draft paperwork and work as a "transaction broker" - I charge 1% or $3000, whichever is greater. 

I have not, but as a licensed broker I would recommend listing on MLS which will post it to Zillow, Realtor.com etc. 

Its worth having your brokers license if you want to make money helping other people buy and sell.

Furthermore, if you are working on refinancing sixth and investment properties at once, I would put all my focus and energy on working with one lender or one broker who can get you the best terms for cheaper cost all your business to one place typically when I see folks do they save a bit on processing these and origination fees.

I would say that it depends on the PM, I personally have a great connection with my local property manager in Memphis, TN and he manages over 700 doors and still answers my clients property management specific questions as the broker/owner.

In most cases due to the transaction sizes, there's very little margin for these 3rd party vendors (particularly brokers, property managers and contractors).

If the latter, depending on the jurisdiction, YOU may need to be a licensed real estate agent/broker to engage in what’s commonly called “wholesaling” but is actually “flipping”.