But after that painful lesson, my practice going forward is that even for investors, I will require an exclusive Buyer's Broker agreement. 

Its always paid during the month, and they are good tenants overall.With that said, however, if you're talking 30+ days late on a chronic basis, then yes, you definitely need to do something about that.

We put a new coat of pain in the areas that needed it, painted the kitchen cupboards and that was about it.

I feel your pain. 

I have seen this over and over again and it is painful to watch.

One slow leak in a toilet can run up a VERY high bill (I see it happen enough that I am painfully aware).

D+to C+ Multifamily properties are a pain.

Financing is a pain with the entity, even if Fannie Mae allows single member LLCs.

and now that I have identified the pain point how would you guys approach solving it? 

They're a pain, and the rates are lousy.