I have a vested interest in not having broken down houses in my neighborhood, and if I can turn a profit all the better.  

Currently upgrading a four-plex in I would say a "B" neighborhood.  

I still own "brick & mortar" real estate but my end game is to be 100% in paper at some point.I upgraded to BP Pro & upgraded my profile.

@Daniel Kenney Yes I would certainly keep some funds aside for repairs, upgrades and operating expenses.

Upgrading the fan to a higher CFM will also make a difference.  

I seldom do large scale remodels, it's usually cosmetic upgrades, cleaning, carpet, paint, appliances, etc. 

Its broken into 6(10) zones I think which zone are you talking about?

I'm planning on upgrading for an additional $18,000 when I can afford it. 

It can lead to cracks in walls, separation between ceilings and walls, and broken plumbing in walls.

Its easy to see that in a year you spend $800 on maintenance from Home Depot, and called a plumber for $300 to fix a broken pipe, or had to replace freon in your AC unit for $200, or something along those lines.