Hi, I am new on here (and to bathroom remodeling) so please bear with me.

I have recently moved into an industrial (meaning REALLY raw) loft space that needs a bunch of work.

The last tenant built a bathroom but didn't finish it. He put up cement board around a claw foot tub ( i figure he was planning on tiling the whole area measuring about 50 sq. feet), so basically what I have is cement board walls. This is my problem, I would rather not tile the space since I have never tiled before and it is an expense that I would rather avoid.

Can I paint the cement board, if so is there a way to prep it so it is smooth-ish?
Could I perhaps throw up some greenboard OVER the cement board?
Should I tear down the cement board (seems like a huge waste) and put up greenboard?

Thanks in advance
-In over my head-