I am from Harrison, AR but work on the road in the oil and gas field.

I'm betting you have not done the math.I suspect Texas may have cheaper natural gas than most of the rest of the country, due to the oil production there.

I assumed it was forced hot air or a traditional oil furnace but great point !

Even with oil prices and the market ultimately cooling down at some point, the rental market in areas with close proximity to downtown will still be robust. 

If this was an oil company claiming that they could make more money if they were just allowed to dump the waste from their drilling operations into the ditch, you would object.

Stained by bleach, embedded oil stains, red pop?  

I focused on Houston more so for the oil and gas industry but unemployment is low everywhere. 

All industries, including RE, begin with some basic business education, then you specialize in an industry, you don't open a gas station without knowing the distribution of gas and understanding what plays on oil prices at your level.

Cap and trade is all but a certainty and the increased fuel and energy costs will kill the economy (even more than they did with the recent oil crisis).

Also, given the location/age, I would assume the system is oil fired.