Just out of curiosity - how do people calculate DSCR?

If you own cash, then you will probably have to get a loan to buy out the other person (most people don't have hundreds of thousands of dollars sitting around to buy someone out). 

People are unloading games all the time.

One tip is too is reaching out to some people in your market place that are doing flips and see if they can send you their spreadsheet they are using.

I’m predicting that people sitting on the sidelines due to rate volatility over the past year will realize that waiting is futile and will stop sitting on their hands.

This is called OPM - other people’s money.

I've been hearing a lot of people re-fi'ing 3 mos after purchase.....at Brew City REI Club's last event, a lender said he could re-fi off appraised the day after purchase but you'd have to show that you did repairs. 

Maybe they are trying to annoy people with low rate mortgages on purpose to get them to refinance (conspiracy theory alert)?

How many people do this?

There are sites out there like passive pockets as well as this site where you can find out a lot from people who have invested with that fund.