If you want to grow aggressively then having the extra cash available to you today is more important.

Rates will usually be in the Prime + 3-4% range if you are trying to max out how much of a line you can get.  

Here in TN we issue POQ within a couple of days of rent being overdue, usually giving them 14 days to correct before official eviction proceedings start.

Just pay extra if you want.

The downside is that you have to share your home with a neighbor and since most of our duplexes are upper/lower configurations you will usually hear them a little - at least know when they are home.

I usually look for 10% return if not more. 

So a majority of the ownership groups would want to sell, plus since they are more sophisticated owners usually would sell through a broker to get max price and not sell privately.  

In reality he is a high paid, likely already working a ton, attorney - he very well may not want to average an extra 10 hours a week of work year round to make it work. 

It’s usually not allowed for rentals.

Almost all mortgage loans these days have Due on Sale clauses, so it comes down to A) whether they find out (usually from changes in the insurance policy), and B) whether they choose to call the loan.