You don't get to tell me you qualify or that you make enough.

Because of my current financial situation, we cannot qualify for a mortgage.  

So the only two ways I know of to change your DTI is to either change the payment amounts every month or increase your montly income.I have been able to work with a bank that will let me do a commercial loan (25% down) and then they allow me to use about 65-70% of the rental income when qualifying.  

If I purchased home with hard money, then did HELOC in 3 months after rehabbing, am I still qualified with conventional refinancing in 6 months?

Be sure to outline how the down payment credit was accumulated and consider adding a clause about a partial refund for tenant-buyers who cannot qualify for a mortgage at the end of the RTO. 

Say after a week or two you have a potential buyer, but said buyer can't qualify for a traditional mortgage for whatever reason (possibly self employed).

For some lenders It depends on your rehab experience, for others it depends on if you can personally qualify for the loan...etc

While I'm asking a qualified/recommended lawyer would be helpful as well.

Then going the conventional route for an FHA 203k sounds good but I need to qualify for that first.

First you buy, rehab and then qualify for Sec 8 housing.