I love bigger necks, mostly. They sit nicely in the hand. I tend not to play with my thumb on the back of the neck and I do have quite big hands.
I rehearsed with my Vintage JD the other night and had forgotten just how good it sounds. You're right on the Vintges choice of colours, for lefties, they need to offer more
I don't know the science behind wood treatment, I guess you can look at it like using hand cream !
It's become a routine now when I clean and restring and I've seen no damage.
I'm not sure about the materials on passed guitars but my current ones all seem to be rosewood.