Use oil based enamel paint.
They have special paint just for pools, one that will hold up under the water. For pool steps use a non skid pool paint, or if you can not find any non skid you can add some silica sand to the paint container. Any Paint supply store should have it and some homecenters.
Bondo is the industry standard.
I would roller it with latex.
i would think fiberglass or some kind of heavy duty plastic
Paint can protect iron from rusting, especially if it is the right kind of paint - you would not want to use a water based acrylic paint, since the water in the paint would promote rusting, rather than preventing it.
Yes, you can paint a design on a vinyl mailbox/post. The type of paint you would need to use is a latex exterior paint. This is the type of paint you would use on the majority of outside projects.
Go to the craft store and get fabric paint. That should do the trick.
its called "sign painter's ONE SHOT"
Humans use fishing poles for fishing
Depends where, and what kind of fish.
There are many sources online that have information regarding the installation of fiberglass pools. Among these is YouTube which hosts a variety of videos about installing almost any kind of fiberglass pool.
what kind of paint does O'Keeffe use