Software is a common question on BiggerPockets.

Looking at pure spreadsheet math and common convention; if you pay down your mortgage you are effectively making that interest rate on your money. 

The market has definitely gotten more competitive, and it’s common to see BRRRR deals over $250K, especially given the high demand/appreciation in the area.

She'd probably have to get a new loan in that scenario however obviously in order to get you off the current loan unless the loan is assumable, but that's the downside of linking your finances on a 30 year contract without being married. 

There are DSCR products for those scenarios, but they generally price worse than regular DSCRs.

Ideally there'd be second factor requirements on any transfer, and especially "suspicious" ones (as defined by an entire team of people who monitor that sort of thing).Cookie theft and other takeover scenarios are a thing.

Common fees will include a set-up fee, a leasing fee for each turnover or a lease renewal fee, marking up maintenance, retaining late fees, and more.

Really good points about anticipating future costs and changes; they always miss this and only think of their best-case scenario.

It was common back in the day.

And in some ways, the DST becomes less (*slightly less*) important in that scenario.