My DTI (on my own) is too high to qualify for a HELOC at the local credit unions that I've talked with, and they won't let someone apply as a co-applicant if they don't live in the property as well. 

The time it takes to get in and out of a co-op due to the co-op board and their interview processes can make exit strategies very tricky in my opinion.  

The $500 is essentially saying they aren't offering a co-op commission.

Does the construction need to be completed and a CO issued before the proceeds can be used?

But that's a good point about a big fish coming in and you make reporte with them and to do that you probably have to advertise so the buyer comes to you direct.. if they come in through a Co broke you probably don't meet them.. 

Given that you are still in college, IF you need a co-signer, talk to someone who you believe would be willing to do so (e.g., a parent or guardian, relative, etc.) so they are aware of point no. 3 and can provide you and the mortgage broker with those same items when necessary.

I run into these situations.One was a co-worker of mine, and his landlord was stupid enough to split a monthly gas bill of $30.00 with him.

Airbnb has a co-host program, where they can show you other hosts in your area who manage their own property and (for a fee) will manage yours as well.  

I know that the FHA says that 75% is the max but her mom also signed with me on the lease for our apartment as a co-occupant.

Funds can come from a gift from family or from a business partner who is a co-borrower on the loan.