Thirdly,
many people have mentioned that the game flows too quickly and we don't have enough time to enjoy each Age. I don't know whether that is a universal opinion, but I do think a significant minority would like an option to have Ages last longer.
The only thing here that I can talk concretely about is this, and I think I (or someone?) has said in a Q&A or on the Discord, the goal for each age is to last 50 turns, but ages will also fluctuate based on player behavior. Some ages you might want to rush out of, it it's not suited to your strategy or you want the next age to come along because it
does compliment you. Other ages will take longer because players want to play with the toys and get distracted from advancing to the next age. (AI will also fluctuate based on difficulty and if they need to spend resources playing with age-specific mechanics)
The first two ages are much shorter than the rest of the game, and are intended as on-ramps to get you started and into the variant ages sooner.
To your other points, all I can really say is that both of those problems are seeped in foundational choices we've made while making the game, and making any significant changes to how NS's work or how the CV looks aren't something we can quickly pivot on.
Personally, I understand exactly what you're talking about with NS ideals costing the resources you want to spend on powers, and you'll see that some NS's rely more/less on power usage or are in domains with powers you want to use more/less frequently, which makes them easier/harder to progress through. And on the CV, we've definitely seen and read a lot feedback.