Stuff changes, things that don't bring in money is left behind
Things that use to be use this or you will damage your drive/motor is mostly smoke and mirrors. So goes Merc, VP and others, so how much is actually real and what is hype?
You did say something recently that really caught my attention. It was something to the effect that going to OB is the way to go for salt water, it's cheaper and better to stick with IO for fresh water. This is the main reason I'm going to go to a Formula 270 IO and ditch my Crap O real OB boat. The OB Merc piece of Crap is way to maintenance intensive
When I get a newer 8.2 with Gen 3 cool fuel I will be changing it over to older Gen 2 or even a Aeromotive (or other) with return to tank option and fix the Merc crud. Time to fix a bad design
I really don't have much of an opinion about saltwater. I've probably only worked on 30-50 salt boats, way less then 1% of the boats I have worked on.
I've seen draining Merc gear lube out of a Volvo drive and refilling (sometimes need to do it twice) fix a slipping cone clutch.
I've seen Special Lube 101 last many years longer on a prop shaft then anything else except Perfect Seal.
Some is hype, but most is real. Take engine oil -- marine certified oil is better -- in marine engines. I've worked at both Hatteras and Tiara dealers. They were both exceptional boats when I worked on them. S.S screws and bolts that had been chrome plated for extra protection. Never 2 dissimilar metals touching each other and many other things that made them stand out against lesser boats.
But does all this really matter in a place like Minnesota? Probably not, but in salt --- probably quite a bit. Depending on the situation "good enough" is ok.
I feel for you on this boat. When I worked for a Chap dealer, they were a pretty good boat. Better then Sea Ray and many others, not as good as Regal or Formula. Merc is a good motor and support is better then anyone. I feel that this is mostly a dealer problem.
My advice to people buying a new boat over 24'.
I honestly feel the dealer is more important for happiness then the brand of boat.
Over the years I've worked at new boat dealers (over 25 different boat brands). I've worked for probably the best dealer in the USA in terms of happy boaters. Also a few vey shady dealers and the in-between. I've seen (and sometimes been part of) what happens behind the curtain. It's hard when a "problem" boat comes along. We are faced with the fact that we are going to have to spend more money then we made off of the sale. When a dealer isn't making the profit margins that they should (and most aren't), They just don't think they can afford the $$$ required to keep the buyer happy. 90% of boat or motor warranty work is done at a loss in this industry. In all my years with the 27-50' boats --- I only saw ONE boat that didn't need warranty work.
All the major builders make a good boat in most models and most make a few pretty poor models. A good dealer can afford to keep the customer happy.
It's easy for me to say, cuz it ain't my $$$$. But trying to save 5-10% going with with a "better" deal, can sometimes have some terrible ramifications.
I've tried to be very clear about the O/B vs I/O debate. Once you get into the 200hp+ range, they both become incredibly complicated. Mercury Marine is very clear that O/Bs will cost 3X in "extended warranty" work in the 5 years after the real warranty expires than a I/O will. Getting them O/Bs that quiet and smooth comes at a pretty high price. None of them will have much chance to outlast a hull. Especially in salt. For a freshwater boat in your range, I think the choice is clear. Don't get me wrong sometimes O/Bs make sense. And lets face it, a couple or three O/Bs hanging off the transom looks pretty sexy!
On the fuel system revamp. Think long and hard. I'm told that the fuel in these high tech motors have "pulses" in them. Each PCM gets it's own maps to work with something as simple as the rubber hose that connects the pump to the rail. I know a company that was designing a CF3 pump to sell aftermarket, they dropped it once they realized during testing they would have to reprogram some of the PCMs. That's getting into EPA's area and most company's are still a little leery of them. Once you change a system like this? Look at Merc, they haven't been able to adapt the FSM to work on their 4.5 +6.2L. Me thinks that if it was easy, it would be done by now.