I used one to purchase my primary residence and got a great rate and took an extra $15,000 for repairs.

I intended to refi when construction was complete and possibly make it my primary residence, the ARV would be $500k or higher if the market stays strong.I called my lender to discuss the end game and she said that she cannot refi on AITD and that they are illegal.

Residential and commercial can both be financed with commercial loans where the acquiring entity's credit weighs more heavily than the business owner's and the building's income production is a primary factor.

Home equity line on your primary? 

My wife and I rented out what had been our primary residence in Washington State after relocating.  

Montco my primary focus is the potential buyer or renter. 

From the date of the closing of your sale you have 45 days to identify your potential replacements and 180 days to close on one or more of those properties and complete the process.However, it sounds like this is your primary residence so it would not be eligible for 1031 treatment anyway.  1031 exchanges are only for investment property.  

Specifically, I have a friend who wants to buy this home as a primary residence, however the seller is not interested in FHA buyers and won't even consider offers contingent on FHA financing.

there is NO question that Californians lead the nation in out of state investments.with the primary driver SoCAL.. there is a reason MI has an office there..

I currently have 4 condos, 1 house, and my primary residence.