Haha glad you liked it!

To each their own! (not sure I'd be advertising the old thing though....

) but with a new game like this, especially one going outside the box compared to previous versions, you gotta try everything out and see what works for you. I say this fully convinced that based on your playstyle, you can find a way to make it better with towns. On the other hand, it goes to show that there are many ways to play Civ VII efficiently compared to previous iterations. What's their saying? "Build something you believe in"?
Well, if you played Civ 1 on release, I'd say you are old by definition

Agree with you that all new mechanics have to be tried and tested, and I'm getting there, bit by bit!
You see, when I'm playing, I always choose a random civ and leader. If I get a civ or leader I have already played with, I go random again. Say I get Friedrich and Rome, but I've already played with Rome, I do Friedrich and another civ I haven't yet checked out.
Same thing when a new age comes around, I exclude the civs I've already tried, and if there's no remaining civ "linked" to my leader that I haven't tried, I use an RNG to pick one.
This way, bit by bit, I'll get to play all leaders and civs. And of course I play to their strengths, to ensure I learn those aspects of the game!
Excuse me?! So you haven't reaped the rewards of 15% science, culture, gold, and happiness across all your settlements following your religion? Have you not done the Exploration Culture legacy path??! It's one of the easiest ones of the age!
Correct! I wasn't even aware of what sounds like considerable bonuses!
By research and random events I've reached the first Legacy option on this path, but never bothered with the missionaries. It was all too micro-managey for my liking.
That being said, I know there are civ(s) that have unique missionaries, so it's only a matter of time before I'll have to play a missionary-centric game and learn all about this.
This confuses me even more....

The game's too easy so you keep doing the same boring thing without challenging yourself?!

Nah, all jokes aside definitely play the game how you want.
Haha yeah that's a good point! I expect the new civs and leaders I play with to provide challenges, and while some do, others are too easy.
Yes, it is true your town stops growing, but the food doesn't disappear, it just gets dispersed among qualifying cities. Additionally, your towns are automatically providing gold from their gold and production outputs. Add a specialization like hub town and now you got a settlement feeding your cities, providing a good chunk of gold, and providing diplo influence. Sometimes, I don't specialize them. Maybe I still need access to resources. Maybe my cities are already good on food. Maybe I plan to convert it into a city. These are just a few thoughts regarding the town mechanic.
Yeah I'm aware of how the system works, I just haven't gotten into it yet. I still don't believe multiple feeding towns are better than cities with all sorts of culture and science buildings providing enormous yields.
But I'm happy to be proven wrong - I'll take up your challenge and do Isabella / Carthage on a Huge map in my next game!
I decided to go with Egypt with the idea of picking Shawnee in the Exploration age. I was inspired by your adjacency comment and moved my settler one spot to make way for a future Necropolis with +5 gold desert and +4 happiness navigable river adjacencies. By the way, if there's a Wonder on a desert tile, would I get double adjacency? I got excited to find Mount Everest early as it provides 4 tiles of +2 diplo influence and it was next to a navigable river, but the AI beat me to it by 2 turns . I decided to adjust my location and now Ashoka is angry with me. Would love to take that Mount Everest settlement away from him but have been trying to go more peaceful and defensive. I'm attempting to see how long I can survive without an Army Commander...not going very well haha. All three surrounding IP's spawned as hostile lol so taking a minute to gain suzerainty. Going to settle my third settlement on a navigable river....We'll see how it goes!
It varies depending on the situation. In the game I mentioned above, all 3 of my settlements are at least 6 hexes apart. I do agree with your thinking that a settlement just 3 hexes away could be more suitable as a town. I've provided my two cents about towns above. Playing Carthage will be your best bet on exploring the town mechanic.
Ouch, tough luck with Mount Everest!
I don't know if you'd get double adjacency. But I'd love to hear the answer!
Even if you're trying to play defensive, you need that army commander! Don't you feel like combat is a bit of a waste without someone to hoover up the experience from killing the barbarians?
Finally, regarding your question about number of settlements / cities:
I typically finish the Antiquity age with 8-9 settlements, of which only 1-2 are towns. I never finish below the settlement cap. And one of those towns comes from capturing an enemy settlement on one of the last turns of the age!
In my cities I try to build as many buildings as I can, except for maybe the last 10-15 turns, as the yields you get from them are so short-lived and near negligible. It's a bit of a problem in this game that those buildings you enable towards the very end of the age are so pointless. But a problem that it's very hard to find a good solution to!
Yes, gold is sparse in the early Exploration age, but prioritising gold buildings quickly helps resolve the situation.
Back to my age, my memory isn't what it once was

, so I can't give you any exact numbers of my GPT at the beginning of a new age. But it's never in negative, at least! In my current city state-focused game, I started journaling a bit, will keep doing that to be able to answer such questions in the future!