My goal is to be able to retire before age 60 (currently in my 30's). 

So assuming you have the recommended healthy reserves that can cover six months of payments, and mostly stable renters, what's the strategy?  

I feel that this property is positioned to become stable sooner than later.My strategy is to Fix to Rent using BRRRR strategy.  

I used to be a real estate attorney (I retired my license, so nothing I say is legal advice), but even when I practiced, I would still use local counsel for land use questions.

They are the most stable in all market cycles, easy to manage, low maintenance, have the highest degree of appreciation and bounce back the quickest after a recession.

I will be retiring in about 4 years.

I've done a fair amount of research on rent to retirement. 

I would imagine it might become harder for a conventional refinance... but if the deal is great and the borrow it stable, the bank will lend. 

With an IRA, there can be no direct or indirect transactions or benefit between the IRA and a disqualified person.These programs are for one purpose, growing your tax-sheltered retirement savings in a more diversified fashion.If you are asking "How can I use my IRA to..." you are on the wrong track.

We can pay down so we can retire off them.