Hello,
"Bubbles" or paint blisters appear when the paint dont stick to the surface it was painted on. There are a couple of common reasons though
1) Didnt put sealer. If the old wallls were spray paint, this is bad. Spray paint are solvent based, and normal interior wall paint are water based. It wont stick. Or if the old walls were dusty and not cleaned first too.
2) Didnt put sealer properly. Sealer needs to be dried completely. Then put the base coat/ top coat.
3) Incompatibility of sealer + top coat. This one can also be another reason. Usually i use sealer from same manufacturer as the top coat because manufacturer's side would have tested ot first.
For the rough surfaces, this one may be true. Paint can only cover superficial and hairline cracks. Paint thickness is only a few microns though, it cannot act as a surface smoother.
Have you got it fixed yet?
