I've encountered a fair number of lots zoned for U-TU-C, and I get excited for my clients only to realize the lot is 4,000 or some such.

I have a sticker up...can't even remember what it says. 

This is one of the biggest problems encountered.

I first encountered these in a VRBO rental and now use them in out sinks just to catch bigger junk before it goes down the drain.

When to send a pay or quit  notice is probably the most commonly misunderstood process hobby landlords encounter.

I always use the 70% rule and inflate my rehab budget by 10 % to account for the worse case scenario and unanticipated encounters.  

I encountered a seller that inherited a house from his deceased father.

For commercial real estate (where you'll mostly commonly encounter cap rate) another common metric is "total return".  

Has anyone encountered a situation like this?

I went through it with them, breaking down the number to get to my offer price.Part of the other problem I am encountering here in New York (not sure if it is the same in other places) is this.