@Smuvers Farm
That stuff is awesome. I used it on the ceiling of a house I bought to cover water stains on otherwise good drywall.
That being said....... If the border crap is cracked and peeling there are a few options. None of which are fun.
Painting over it you will still see the outline and cracks unless you skim coat with drywall mud.
Replacing all the drywall would be a PITA.
To skim coat mix the drywall mud thinner then if doing seams and get a big knock down blade (special tool for doing knockdown texture), spread the mud and use the blade to smooth it.......then the sanding and sanding and dust begins. Not a favorite task for me.
I would get some Kilz and try it on a section that has crackling to see if it can fill it. It is kinda thick, certainly thicker then latex paint.