Wade Cook, Segal and the other gurus. 

One of my properties uses oil based furnace as heating source and has a buried oil tank.

@Cody Cook The slight drop in price per square foot could be attributed to many things.  

Electric baseboards are 100% efficient - 1 unit in 1 unit out, and energy efficient oil furnaces are ~90% efficient - 1 unit in, 0.90 units of heat out.Yes, the heat pump will become less efficient in the coldest time of the year, and all that means is you use the old less efficient system for a portion of the year.  

Standing timber, oil/gas resources, etc., come to mind.

Kilz (oil based) does a very good job of covering odors.

Hello @Steve Cook I think that your ability to secure a HELOC would depend on the amount of equity that you have in those homes.

@David Cook We self manage and have done very well even with a transient career.

Without typing forever, I can only rationalize that Texas is what it is because of the oil and gas industry.

I'm looking for:Good school systemsLow crime areasResidential areas with few rentersQuiet side streets, cul-de-sacs are greatClose to amenitiesClose to transportationMust be positive cash flowBargain priced is usually a good thingNot next to:  highway, bar, junk yard, sewer plant, commercial area, loud areas, negative things that you can't change.Non flood zone areasPublic water & sewerNon oil heated housesYard not too large or too small