Joe,
It's just my opinion, but here goes:
Of the items you mentioned, the only one(s) I think add value would be the Honda generator and the a/c. From my perspective, the other items (shorepower, battery switch, trim tabs, swim step ladder, compass, etc) are items that one could reasonably expect to find on a CD22. I don't see the cost of installation of any accessories (particularly on a 12 year old vessel) as being a value add-on. (My sole exception there would be if Dr. Bob installed it!)
Accessories are nice, in certain circumstances. Then again, particularly with electronics, the older items may not be the technology YOU want ... and they're probably more prone to wear and/or breakdown. With other customized accessories, it has a lot to do with how you'll use the vessel. Some fishermen(fisherwomen too...

love having an outside helm and downriggers. To me that would be bothersome. The same issues might be said of accessories like the Wallas stove, Espar heaters; they might be Great, then again they might not meet YOUR particular needs.
For us, things like an opening front window, good camper canvas, a windlass, an autopilot are fantastic - to other folks they might not have any added value.
I would tend to look at the overall vessel and its larger components. Is this the engine what you want, and what is the condition? Personally, I wouldn't quibble over any modern 4-stroke engine if properly used and maintained. There is a current thread on Honda carbed 90 and the newer Honda EFI 90. I certainly like the EFI model (I've owned both...) but I would certainly consider a carbed Honda if the over all deal was attractive. Same issue with the trailer. I like a bunked trailer versus a wheeled version; but neither would be a deal breaker.
Good Luck!
Best,
Casey&Mary