Thanks for sharing your thoughts and experience, Kayakguy (Bikeguy, too, apparently!).
I ended up finding all the things on my "must have" list (and one of the two things on my "would like to have" list) quite unexpectedly at a local bike shop: namely, an Aventon Level.2. I test rode about a dozen bikes there, priced from $1995 to over $5k, with and without CVTs, etc., and picked the one that--specs aside--was simply the most fun to ride, and by quite a big margin, actually. To my great good fortune, the "most fun to ride" bike also happened to also be the lowest-priced of the lot! It does have a chain and derailleur--which, when I was in the online research phase, I thought I wanted to avoid. But, when I got to the test-drive stage, I found that I agreed with Ahicks, who wrote the following about CVTs in his post above:
"Gone is the clean, precise, quick, snick snick, of the derailleur shifts, to be replaced by a much more vague type shifting. Nothing terrible, but I do miss the quick exact shifts of a well maintained derailleur."
So, I stuck with the "snick, snick" and am feeling content with that choice (especially considering the savings, and most importantly, that the gestalt of this bike, for me, was just that it felt the most fun, easy, and natural to ride of all the ones I tried.) I'm really happy with the Level.2. Love the torque sensor, front suspension, 27.5" wheels, step-through frame, throttle, front suspension, and several other thoughtful details (metal fenders, really nice tail/brake lights, high-capacity rear rack, USB on the color display). I added a Kinect suspension seat post in deference to my lumbar fusion, and I'm off to the races!
P.S. About a month after I bought the Level.2, I got a chance to ride an Evelo Galaxy, which had been my front-runner during the online-research phase, during which I started this thread. Other than being lighter, which was nice, I liked the Evelo less in every way than the one I ended up with. Test rides are really key, it turns out!