Re: Bottom paint
That keel looks to be in terrible shape. I'd suggest stripping it all the way back to shiny metal, priming and repainting. You may need to chip away the patches of scale and if you wanted a fair surface, you will have to fill and sand these areas. If the keel looks this bad, it might be prudent to check the cable or whatever system you have to bring it up and down, as it seems the PO wasn't too big on maintenance.
I can't tell on the hull, but it also looks to need some loving care. I'm not so sure a barrier coat without paint (not necessarily bottom paint) is the best way to go.
"Any idiot can make a boat go; it takes a sailor to stop one." Spike Africa aboard the schooner Wanderer in Sausalito, Ca. 1964.