Jeff, thanks for the update! Might want to be careful about switching ECU's from one engine to the other, I believe they are programmed to operate a specific S/N engine? The mechanic should have recorded the fault codes before switching out sensors/switches! Also, your good idea, take the vessel to another marina with a VP certified mechanic or call VP and ask them for a recommended dealer in your area!
Regarding your drip less fitting I have learned over the years "if it aint broke, dont fix it"

(But do service it as recommended by the manufacture)
Good luck and yes, part of boating is being able to drive the boat, the other part, in our case, is just hanging out at our covered dock with slip mates for a short weekend. We are happy that with a 2001 we havent had any problems with the expensive stuff, i.e. engines, gears, gen set. Just little expensive stuff!
By the way, where are you docked, lake, ocean, or inland waterway?