I have been aggressive in getting rid of oil heated building by either selling or converting.

If the local job market depends upon oil and gas for example and oil and gas drops and many jobs are lost that will really hit you. 

Also a future business partner who works in the oil field and has more money than time.

If it's in an area that I (and/or my property manager that I trust) don't feel comfortable managing it then it's a deal breaker.Rent Control - (state / city specific) - there are ways to work with it (e.g. increase rent due to hardship) - that can be fixed.House condition - roof leaking, oil tank, house needs renovation - again, that can be fixed.Neighborhood - you can't really fix it by yourself, so either it's already a YES or a NO as-is. 

is anyone worried about buying in OKC right now because of oil prices and layoffs in oil related companies?

People wonder how oil prices will affect our market in SA as well.

Clearly it works well for the oil companies.

Kim,  Normally using a really good OIL BASED primer does the trick.  

To me a only major red flag would be if the property had some sort of environmental issue such as a leaking underground oil tank.

Electric, gas/oil would be the responsibility of the tenant.