It depends on what you're trying to do. Follow the manufacturers recommendations for all auto body painting.
Yes, you can.
I would use at least 3 coats of primer sealer. It's not very dense and will waste the whole job if not done properly.
You can't. Prime over it with a good primer.
no
Yes you can, although it will adhere much better if you spray a primer first.
It is able to, but is very hard to dry, because it takes a loooong time.
Yes, you can if you are sure you need to.
Any oil based chalky surface sealer should lock the calcimine down, providing a stable surface that will accept any latex ceiling paint.
Tremclad makes it in regular paint or spray. The spray is better, especially if sprayed over a flat white primer they also make.
You do NOT use regular paint as primer. It contains none of the qualities of primer.
You should not need a sealer over latex paint. If you sealed the paint, it eliminates the breathing it is designed to have thus compromising the paint, and may cause it to peel together with the sealer.
Yes. But you can't do the reverse. So if your primer is lacquer-based you can spray an over-coat of enamel on the top.