Again, I don't have the facts here and I'm not giving you legal advice, but I think you might benefit from talking to an attorney and getting this all sorted out. 

This is what I did, called about 40 local banks and credit unions, found numerous who would do terms that no other traditional lenders I spoke with could or would do.  

After numerous monster years, I fear not being able to that year after year.

As long as the numbers work, it will be to your benefit to secure as many units as possible with that cheap 30 year traditional financing while it's available to you.

I recently had issues finding financing at an 80% LTV (i.e. 20% down), most banks wanted to lend at 75% LTV (25% down), but I called numerous banks (probably around 10-15) till I found one who would give me 20% down.

What benefit do you get from a business account that you don't get from a personal account?

I didn’t think about the benefits of PMI.

The seller gets the benefit of enjoying interest payments, which will give them more of a profit than a regular sale.

Finally, I usually will consider about a .5% appreciation rate per year for overall appreciation (non-cash benefit, but can come in handy down the road), increases net worth slowly without taxes.Hope this helps as well. 

Tax benefits are also amazing, but don't let them dictate your analysis.