Simple buying apartment buildings 5+ units,  "semi distressed", class B neighborhoods,  using very ordinary traditional financing (20% down, 20 year, reset every 3-7 years, etc.) -- Why?

Reset everything.

Our bank has been good about letting us reset that 5 year lock every few years to keep our rate lower. 

You're paying a fee to refinance, paying more interest each month (due to the higher balance) and foregoing future lower interest payments (by resetting amortization each year).  

Also if the lienholder sells the mortgage does the lienholder period reset?

I do not believe you can do this a third time (even doing it a second time is very tricky).But once the loans are paid off, your entitlement resets and you can use the full VA loan benefit again for a primary residence.

Albert, I think I'm remembering that cap wrong and got it confused with a 7/1 arm that I had that had a reset cap of 7% after 11 years or something like that.

Food disposals (including how to un-jam with the provided wrench, and where the reset button is), certain types of tub spout diverters, GFCI outlets, circuit breakers, etc.

I have a couple of questions regarding tax lien investing, specifically in NJ.1) If I've been paying subs for a year on a lien I own, and the property owner sneaks in a quarterly payment after a year, can I still foreclose on the 2 year anniversary of the original tax certificate sale, or does that clock get reset because of that one payment?

We were overdue for the reset, and while a pandemic isn't my chosen reason to kick it off, I think now that it has there's next zero zero chance of things recovering to exactly where they were at the peak within a short span of time.