I don't really want to invest in a D-class area.Tangentially, what are some of your "it's time to sell this property" red lines when it comes to the changing economic conditions of an area? 

When you can enter from a position of strength financially, the risk:reward ratio significantly changes.

Also I have done it in the past whenever I had a change in plans and they never had the opportunity to actually be selected. 

The current owner listed last years income as $51,000, but currently has rents at (for the five separate units): $650, $750, $800, $825, $1125 (the math doesn't totally add up so maybe he changed a rent payment at some point). 

These changes can significantly shape how properties are managed and have a real impact on your experience and ROI. 

And you don't have Schedule C to deduct the business expense.This might have changed if your RE portfolio was run like a business and/or you have a partnership; the partnership would then deduct the travel expense as an ordinary business expense.As I said, it gets complicated quickly.

If I read this correctly, this essentially changes the 2 of 5 rule to 2 of last 10?  

Changing jobs!

One approach that I have not seen included in the discussion is as you are still in the planning phase, you could change your approach and the facts to make it more favorable for your strategy.

Ultimately it's less of a science than an art, but people rarely truly change so what they did is probably what they'll do.