Those are all good suggestions. I'm planning on a shaft brush and also connect to the engine, rudder shaft and rudder tube.

I had a BFO (brilliant flash of the obvious) this afternoon and called the guy who dives on half the zincs in Seattle and mine. No surprise that he likes the "Diver's Dream" zincs and he endorses using studs that are welded together via a plate on the inside of the boat, using 5200 or other aggressive adhesive/sealant to keep water out. That way, the diver can't break the watertight seal while removing the old zinc and putting on the new one. So, I'll be going with the Mini Divers Dream plate (by Sea Shield) and snug it up next to the hull for (hopefully) minimal drag. That should provide enough protection. If not, I'll just have to add a bigger one later! One thing we like about these particular zincs is that the contact is steel which is embedded in the zinc, so it reduces the likelihood of erosion near the stud resulting in the zinc falling off.

I may provide for a zinc "guppy" for use during the winter at the dock, just to extend the life of the other zincs.