For metal isolation, such as fasteners, there's the usual; TefGel, LocTite, etc.
You'll need to be sure that things like your through hulls, & ballast are also isolated from the hull. For some things, like larger bolts, you can get isolator sleeves, or have them made. And all such fittings, noble metals, & through hulls need to be well & properly bonded.
Plus, if the boat doesn't have them already, it'll likely make sense to have tapped pads welded to the deck, to bolt all of your deck hardwae to. Which is a two fold help. Since they're welded to the deck, you shouldn't have/get any
leaks from your deck
hardware. And, they add a bit more "meat" to the (hull &) deck, in locales where you'll have more in terms of
stainless steel fasteners.
Unfortunately, I'm a couple of thousand miles away from my sailing library at the moment. And in it are lots of reference
books which cover how to handle a lot of what you're up against. But such
books are easy enough to order, & should serve you well.
Again, Nigel Calder's stuff is a staple/good starting point. But Definitely also get in contact with the Metal Boat Society. I'm thinking that they're likely a wealth of good information.
As to your
electrical system. Probably your best bet is to sketch out what you want in terms of; lights, fans, & other devices. In addition to how you want your harness & panel(s) laid out.
Then take your sketch, notes, & ideas to a pro, so that you can have the system properly designed & up to spec. Including putting in some extra, unused/un-connected wires, for things which you may
wind up wanting to add later. Ditto on getting pointers on setting up your conduit system.
That, & of course, buy Nigel Calder's works on the subject, as well as those by the ABYC. Or works which have
references & guides to the ABYC's rules on putting together such systems.
Ah, & you'll need to become a bit paranoid about avoiding dropping small pieces of wire into the boat/bilges, when you're installing any
wiring. As loose copper is bad Juju in an
aluminum hull.
And were it me, I'd consider hiring a
project manager or good
marine electrician, on a part time basis, to check up on my
work, say, once a week or so, when the re-wiring was taking place.
That way, I'd know that everything was up to spec, & that I hadn't made any major blunders along the way when installing things.
You'll also be
buying a few zinc "fish" to hang in the
water (from the boat), for whenever the boat's not underway. They help to protect the boat from stray
current in the
water, as well as any
electrical leaks onboard. Plus aiding in protecting your more permanently mounted zincs. Such as on the prop shaft for instance.
That's far from everything, & I only have a working knowledge of metal boats. Thus my recommendation for talking to a few pros, & some high end amateurs.
Ah, & you might send Evans Starzinger a PM, given that he & the Mrs. had an aluminum boat for a number of years.