The chimney is a wide column in the middle of the living room. The finish on this chimney sort of evokes brick, but I don't think it is. It reminds me of stucco, but it isn't that either. The house was built in 1975.
I'm trying to determine what it is so I can answer the following questions:
Can I remove the bumpy finish, make the indoor surfaces of the chimney smooth, and paint it?
What's usually behind this kind of finish on a chimney? Brick? Drywall?
If I wanted to screw a pull-down flatscreen mount above the fireplace, how would I anchor it?
Close-up of the material:

Picture of the room for context:
