Re: outdrive paint
I've seen very detailed recommendations that include stripping, acid etching, and using two part paints and also hear people talk about just grabbing a spray can of rustoleum in your favorite color. For what it's worth, I think it makes a big difference if it's a freshwater trailer queen or a saltwater boat that spends it's life in the water. If you do a google search for "outdrive painting" you'll see that the opinions and methods vary.
Since mine is a freshwater trailer boat, I scrubbed it down with detergent to degrease, washed with mild soap and a greenie pad and then went over it with 400 grit wet/dry emory cloth. I touched up the bare spots with a self etching primer and then sprayed several coats of an aftermarket outdrive paint. Some say that you should also wash the aluminum down with a vinegar/water wash but I thought that was for painting galvanized.
I think you need to look at your application to determine how much effort is warranted.