How do I go about ensuring that at the time of closing, the total cost of fixing plus my fee for the fixing and coordination gets into escrow and I get pay out at the time of close and my brother only gets the remainder from this sale?

If those are the requirements you have for ensuring that a deal will cash flow, and possibly cash flow better than your conservative projections, then stay true to them.

Mold, rot, electrical, bad floor plan all can be fixed fairly quickly.

Your real estate agent should be able to guide you through the FHA regulations fairly easily.

The % of lot price in whole project makes a huge difference.I would ask for equity equivalent to ~150% of current fair market value of the lot.

This is just my experience with HELOCs, I’m not licensed to give any kind of financial advice, check with your accountant or financial advisor to ensure you are utilizing the correct financial products to reach your goals.

Any other creative ideas for getting the property and ensuring positive cash flow?

I am working with our attorney to ensure that is truly the case. 

Ensure you set minimum criteria for Cash Flow in your Analysis.  

In addition to ensuring there are no legal issues clouding your ownership, that will also give you six additional months to clean up your credit score and also to establish some work history.