Hi again Naid, I cant have my bird-brain to reply to everything posted on a multitopic thread at once, so I usually only take a part of the thread and focus on that, to comment on the UI stuff.
Took out a bit of your post and numbered it, consider the other ideas good and agreed with 
1: In the Enchantments tab, it would be helpful if the enchantments were listed alphabetically by city. That makes handling large amounts of cities easier. Right now they are listed by the order in which they are cast, which does not help very much.
2: Also with the city title and building tabs, it can be difficult to tell how many enchantments a city can have cast on it. A simple change would be to have empty circles where the enchantments could go, and as you cast enchantments their icon appears as normal, filling in the circle. This is an easy reminder to cast enchantments on cities.
3: When a city is selected, as well as when it upgrades, it would be nice if you could clearly see the city type (town, conclave, fortress) so the player has a better idea of what to build there.
1: You can already make the enchantment list sort by alphabet, source, upkeep, and... something else
... by clicking the tabs up top.
2: There are already markings on the overview of the city, tiny half-circles carved into the city's title overview thingie, (the big sign hanging over each city when not in cloth map view, with name on it etc.)
3: I agree with this, except I also want to see grain, materials and essence of the upgrading city! 
Sincerely
~ Kongdej