Re: Safe to tape ?
From your post I assume that the ceiling is textured the same as the walls and not acoustic or "popcorn". If this is the case, don't tape, you won't like the results and it's pretty labor intensive to install decently. A faster, easier, and better solution is to run a bead of caulk in the corners. This fills the crack and hides any future cracking that may occur in the corners but here is the important part, it fills in the lumps and bumps of the texture and gives a slick surface for your brush to run on, making cut-in a snap and you'll get nearly perfectly straight lines. With tape you'll get bleeding under the edge no matter how careful you are.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!