But, you will likely have some long-time residents that will consistently be behind market rates for a variety of reasons.These "rule of thumb" measures can be misleading.  

If you return $100K but it cost you $30K to do the refinance, that's a pretty steep fee.At the end of the day you want to model a variety of scenarios and retain optionality to what will be best for the deal and your investors when the time comes.

This site was recommended to me as a great source of expert advice, so here goes: through a variety of mishaps, the homeowner's insurance for the property I own in Connecticut has lapsed for a bit over 90 days.

I have a variety of investment: rental property, stocks, ETFs, some bonds, and laddered CDs. 

You can find sales comps very easily on Zillow or Redfin, but make sure they are recent you can find rental comps with rentometer and you can see active rental competitors on a variety of sites including Zillow.

I have interviews Marine Bank in Melbourne and they seem very easy to work with and do offer a variety of portfolio loans. 

Apartment investing , flips and pretty much all varieties  of RE were on a major upswing, Interest rates were low , financing was relatively easy to qualify  ..

There are a variety of ways to incentivize them to pay on time.

Treated with professional grade products such as bait gel, growth inhibitor, bait stations, diatomacious earth, boric acid, raid, bleach in the drains, and more.

BP site offers variety of information and resources for your target investments.