Can anyone tell me things I need to consider when painting knockdown textured walls? The house we recently purchased has only this type of ceiling and wall finish.
First of all can you do it - one article on line recommended against it. Do you use flat, eggshell, etc paint? Can you do faux finishes like ragging, sponges, dual rollers, color washing, etc. Any help is much appreciated.

Yea I think you can paint the walls but the ceiling if it's a popcorn ceiling, it depends on how it was blow up, if they used primer and mixed paint in with the texture your fine , if not what will happen is the paint you use will reactivate the texture and it will start to come down, you can kind of avoid this buy only rolling one way, don't paint like you would a wall.

As for the wall texture, its sheetrock mudd and you should be fine to paint or faux anyway you like