Spent about a week there back in June (around the 10th to the 20th). Also commented on a similar thread, but a few callouts specific to your questions:

-The C/O side was pretty full in terms of chairs being used, but there seemed to be less activity in terms of people mingling in the water, hanging around and chatting, etc. so at least the experience for me was a bit more serene. I didn't see any dancing/music, but I spent most of my time at the far south end. I'm not sure even if there were any cruise ships in port when I was there, but I can't recall seeing any cruisers/tour groups this time.

-From a demographic standpoint, I'm 36 for what it's worth and spent the entire week on that part of the beach pretty much everyday except for a jaunt over to Pinel. The crowd pre-Irma was a bit older, and it remains so today from what I could tell. There were a handful of younger folks, but not a ton and I'd say late 40's/50's/60's is most common.

-The latest I was on the beach was around 6PM. It dies off quite a bit after 4PM IMO. It is nice once the sun goes behind the hills so I did enjoy the late afternoons, the different colors you see in the sky and water, and it feels like the wind died down a bit the afternoon I stayed later.

-In terms of your wife's comfort, for what it's worth I walked the beach from where Pedro's use to be to the far south end past Papagayos at least 3-4 times every day and I am completely natural (don't shave/trim). While I wasn't inspecting, most are probably groomed/bare, but if I got any looks I chalk it up to being spectacular and I am not shy lol! She won't stick out either way, although now I'm curious if I did ha ha.