How much interaction should i be having with actual buyer of property and or other wholesaler for negotiation?

You can have whatever language you want in an agreement and while it does matter, that's not really the first concern you should be having if you're just getting started in wholesaling.

You have trained your tenants to behave in this manner.

Any local DC insight would be helpful and appreciated, I am also out of the DC area for at least a couple of weeks so will be having to work this remotely until i return.  

In this case an appropriate comparison would actually be having one or two vacancies out of 20 SFH (or whatever number would equal the value of the MFH used in the example), which wouldn’t be that bad.

Agents have access and connections you don't (yet), otherwise this wouldn't be have been posted.

Well a 2nd concern would be having to do it over again in 2 years, are there quite a few fees to be paid for doing these HELOC's?

People tend to behave when you collect proof because its no longer a he said she said issue. 

The con would be having spent money and still be pretty much at square one without having actually done an investment. 

I look at the guys from CT Homes and they seem to be having fun while making a lot of money in the process.