I have a somewhat different take on chains. My experience has been that fine tuning the chainline has a lot to do with a quiet chain. Once that's done, then using the right lube makes all the difference in the world. I am pretty persnickety about measuring chain wear and I keep records on my components and bike maintenance and have for years. About two years ago, I had started fiddling with my chain line and after adding a crank spacer noted that the chain was typically quieter than it had been before. Simultaneously with that, I had been looking at some of the lubrication data that Friction Facts and some of the other testing guys had been putting out on lube effectivity. At about the time I decided to make the switch from oil based to wax based, Silca came out with their wax based lube.
While the chainline didn't seem to affect the longevity of the chain much, it did make it quieter. I would hypothesize that the chainline caused more wear on the side plates from being out of alignment while chain wear as measured by chain length measurements is wear on the rollers. Adding the Silca wax based lube on to the configuration made for the quietest running chain I had had. But what was really interesting to me was that my chain wear went down (chain life went up) dramatically. Where I had been getting around 1500-2000 miles from a chain, I now was routinely getting well over 5000 miles out of a chain with the same wear measurements. The chains just wore dramatically less. It's an easy fix and the Silca lube is pretty good.
So what I got out of this and what I would recommend are two things: Play around with 0.5-1mm crank spacers to see if that quiets the chain to some degree (if it does, shifting will likely improve too). Secondly, shift to one of the wax based lubes after a proper chain cleaning in line with the lube manufacturer's recommendation. I think it's pretty easy for the tight chainline specs of the day to be slightly out of whack on a bike. It doesn't take much for it to get somewhat noisier.