Texturing over paint ?
 

So my kitchen had a terrible sheetrock job.... actually pretty much the whole house. Unfortunately ripping out the cabinets and rerocking the whole thing isn't plausible considering we're living here right now. I'm fairly confident that I have the skill it takes to fix the ugly looking seams, but i'm not sure if joint compound will stick to a painted surface? While i'm at it, i decided i'd just texture the whole room as well. i'm fairly certain it won't stick well to dirty surfaces, so cleaning will be an obvious first step.

I would sand the whole ceiling to rough up the surface.
When your finished the repairs prime with Texture primer.

Yup
Scuff sand it first

The actual proper way to repair is the prime/compound/prime
Small spots you can skip the first prime. but scuff sand for sure