Painted the entire interior, removed indoor/outdoor carpet in kitchen and replaced it with vinyl plank flooring, new carpet throughout, new bathroom flooring, vanities, faucets, sinks, light fixtures, medicine cabinets etc.

What many people discover is that they're already really good at something else (business, medicine, sales, etc). 

How long will this trend continue and what happens when we see this artificial uptick reverse trend?

If the tenant is paying rent then creating an artificial turnover is usually not in your best interest.

How long can they keep the interest rates artificially low?

They are artificially held low.

I would make sure that the exit cap rate is not lower than the purchasing cap rate as this can artificially boost the projected returns.  

Even if it's artificially high at first, it shows your intent.

If you look at it 20 years in the future, when you'll still have an interest rate locked in at a freakishly (and artificially) low rate, you'll be fist-pumping excited! 

Regulatory burdens are likely to go up, and I think asset prices will remain artificially high due to loss aversion.