Need home improvement advise....?

As a professional painter, we have found little problem applying a a primer sealer over the ceiling. Make sure the primer is suitable to go over heavy smoke stains. "Kilz" is the name of one that has been around for years but most of the major paint stores have their own version. Using a thick nap roller is ideal for a popcorn ceiling. I would use 3/4 or a 1" thick roller. This should make the job easier.

Stripping the ceiling shouldn't be necessary unless the plaster/popcorn ceiling is delaminating.

It will likely be necessary to prime all the walls as well. It will depend upon the extent of the damage. You can do a test sample after you wash the walls. Poor or uneven coverage of a decent quality paint will be a sign that the walls will need to be primed also.

I own a professional painting company in Washington DC. We would be happy to further explain this or answer any of your other questions.

Popcorn ceilings date a home and need to be stripped off. Those types of ceilings are hard to clean and keep clean and they are dust and dirt collectors. The main thing is no one wants them in a home any longer so you would be better served to get rid of them.

If you can do it yourself (physically) then you should scape the popcorn off (easy to resell a home that way). Otherwise paint with KILL's ($ 20 at Home Depot or Lowe's) primer. You might want to get rid of the webs and dust first. Good luck