Topcoats are not really a big trend nowadays. However, one can find them quite easily at vintage thrift stores. Sites like Amazon and eBay will be very helpful for finding topcoats.

The first classification of coatings is by their use in finish systems--primers, one-coat enamels, intermediate coats and topcoats. The term "finish system" includes single- and multi-coat paint finishes. Primers are the foundation of the finish system. They provide corrosion protection to the substrate and act as a suitable base for subsequent coats.

Yes you can. Use wet and dry sandpaper bout 800 first. Then use a primer called grip lock. U can use oil based or water based topcoats on the grip lock but just remember that furniture needs hard wearing paint like enamel. Enamel paints come both water and oil based.

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern --PC-A-S. That is, eight letter words with 3rd letter P and 4th letter C and 6th letter A and 8th letter S. In alphabetical order, they are:

topcoats

Usually you would use either a lambswool or medium pile mohair roller. Foam rollers are only for Topcoats generally, or maybe the very thin film racing antifouling such as VC17m or VC Offshore by International. Worth having a couple of types of roller with you, and see which works the best accoring to the smoothness or roughness of your hull.