(I have a background in engineering and experience with rehabs.)It's right at the top of what I can qualify for on a personal mortgage but when I add in other revenue generating opportunities things quickly change.Before my wife and I jump into this I'd like to reach out to the experts. 

Since you're a U.S. citizen living abroad, non-QM (non-qualified mortgage) programs designed for foreign nationals might be an ideal solution for your situation.

Has anyone successfully qualified for a mortgage in a similar situation?

A DSCR product is what you are looking for.DSCR simply doesn't take into account your personal income, instead we qualify the loan on the properties rental income (or projected rental income).Your credit, properties cashflow, loan to value & prepayment penalty are going to be the main determinants on what this loan looks like for you.

Where I see the builder incentives and builders hurting is in starter housing or housing for rentals that investors are buying.. everything there is interest rate driven.. with land costs fixed and building cost not coming down , interest rates rising this hurts builders who are building product for those that MUST have financing to buy and are barely able to qualify IE starters..

If you consider yourself a "qualified individual" to make such estimates - maybe.

Keep in mind with the FHA loan on 3-4 units, there is a self sufficiency test as part of the qualifying portion.

I don't think your second idea is bad to ensure things are found and documented.I ended up qualifying for a SBA disaster loan that helped when FEMA would not do anything since my properties are under a business.  

The hard parts are ensuring you can have a home that can be licensed for as many residents as possible (comfortably) and finding a well qualified operator to lease it to.

If your property qualifies for a higher amount, the housing authority will let you know what they can approve.