House we just bought has problems with it's gas heater heat exchanger being rusted and possibly a source of CO. 

Here's what I figured out when I add up my weekly costs:$100 for hotel$100 for food, gas, etc.$550 per week in lost rent$750 per week is what it cost me to own the triplex in both actual and opportunity cost.5 days (normal work week) of my labor (40 hours) will take me about 1 months worth of weekends to complete.

I suggest you learn the business first (which a license will NOT prepare you to do) before tackling more sophisticated principals.I will be selling one of my probate properties, which happens to be in RC, in several months however my agent gas been selected as he is an expert in selling properties requiring court confirmation.The best ROI you'll ever get is from continuing your education. 

I would add that it must make financial sense (i.e. gas expense, time, price point, and ROI).

Start by charging small things, like gas or groceries. 

The oil and gas industry is doing a bunch of layoffs (tens of thousands) so home prices are dropping.  

Smell of gas or something electrical that could be a fire hazard.

These assets would be businesses, larger real estate if it makes sense, and oil/gas options.  

Dude - this means you're paying gas.

This tells you from the outside that there is opportunity to add value in updating the property, but also, the inside may match the outside (original cabinets, pink tile in bathroom etc.)Aside from deferred maintenance, look for properties that are on busy streets, next to a gas station, or has any challenges to them.