I had another client call me and he paid 20k for basically nothing..

Very easy communication and they have vendors on call if work is needed on the house, like my did.

We don't want to field zillions of after hours emergency calls for locked out roommates and their parents in the middle of the night, when there's nothing we can do save for drilling a lock or breaking a door (which would then need to be secured). 

Call and schedule an appointment, inflation may have changed that price.

You need to network and search online; you cannot get a list of wholesalers.Attend REA events in Detroit or search online for keywords like  "We buy houses Detroit" or Sell House fast Detroit" and call the companies that appear in the search. 

Unfortunately, all the lenders I have called so far do not lend on multi-unit properties.

Call their commanding officer and they will force the person to settle up.  

I networked with Real Estate Agents and they called me about this deal.

Looking for someone with experience willing to mentor me, give me some tips on making calls and closing.

That's understandable but you'll be dealing with a call center.