It's always best (for the best quality) to paint with primer first, then your regular coat of paint. Let the primer dry sufficiently.
No you can not use primer as your paint because it has no sealing properites in it.
Yes, you can because brown primer isn't that dark of a color.
No
yes. However, you cannot use an oil base paint over a latex primer. If you change your mind on the paint, you must strip the paint before you use an oil based paint on the primer.
You can remove paint primer from linoleum with hot water if the primer is Latex based. Simple wet a cloth with hot water and put it over the paint. Let it sit for a few minutes and then gently scrape up the primer.
To paint galvanized metal you need a special primer. Look in a paint store or home supply store for a primer for galvanized metal. After the primer coat dries you can use any exterior paint.
Start with a primer, Perma Seal is great. then I would use oil based paint.
If you use a quality primer like Kilz or Bullseye, you should be OK.
No, you buy the primer separate and paint with it first, let it dry then get the paint and paint over the primer. There are several paint applications where the paint can be used as a primer, and this is called a self-priming paint. In addition, many paints are marketed as a paint and primer in one, however, that refers to its ability to adhere well to a surface and to cover the previous coat. In more difficult priming situations, like staining or painting with a very dark color over a light color, it's recommended to use a dedicated primer followed by a top coat.
You paint it with epoxy primer.
You didn't mention whether you were using latex or oil based primer and paint, but generally the point of using primer is so that you can paint over it with any form of wall paint. Just read the label on your primer can to make sure it is compatible. On the other hand, if you wanted to paint the primer over the satin gloss, you need to sand the surface lightly to remove the sheen of the paint and provide a suitable surface for the primer to adhere properly.