Great question, I'm glad you've enjoyed your visits to San Diego. 

Leach field, sewer pond, etc. 

In some cases 1 year of tax returns might be acceptable if it's in the same field.

We're next to a public ice rink, tennis courts, and high school track + fields.

But, like everyone else; my goal is to have multiple properties.At what point did everyone begin to enjoy the fruits of cashflow rather than save it and roll it towards another DP on the next property?

If things don't work out you simply terminate your leasehold interests, but if things do work well and you enjoy working with the current owner you put yourself in an ideal position to put very favorable seller-financing in place down the road since you are the one that has been managing the building, removing his tenant headaches, and already sending him a check each month.

I enjoy seeing things work out and growing them 

If you're looking for others that have come from the medical field I would recommend connecting with any of these folks.

I've enjoyed every BP book that I've read.

Was a student athlete so you can imagine what it was like having school, practice/games (events I was a track and field guy) and then work.