It is a large sum so I would think carefully about it.

If they will be turning around and renting it our, then they would get a Rental Dwelling/Landlord policy.The seller should be added as an additional insured as they still are tied to the property and could be named in a lawsuit. 

You may have built enough equity in the first to be able to refinance to conventional without much added expense.  

Is it okay to say to my realtor, "Hey, help me get this deal done and you'll make your money when we buy the large multi?"  

The plot also contains 9 studio apartments.

The reasons wholesalers make money are essentially 1) speed to close, and 2) large deferred maintenance that precludes typical sales.

This way they are not incentivized to go over budget and they have an added incentive to come in below the GMP.We do this all the time on large projects.

I don't have personal experience with a HOA ever lowering dues back down but then I never experienced such a large increase.

That is great and you are stepping into a large amount of doors that are already performing!

Something is off here.For a conventual loan on something around the $150k house I pay around 2%.Hard money, commercial loans, or double closes will cost more as there will be points added.