"Religious Identity" is already in the game (sort of) in the number of Followers of a Religion in each city.
"Cultural Identity" could be handled the same way, in the number of people in each city following your, or some other, Culture/Social/Civic combination. This also opens up a 'mini-game' regarding Loyalty and Internal Resistance to your central government and governing group among the Cities and Population, and should require some reaction/action on the gamer's part to variations and multiplicities of Cultural Identity within the Civ.
Total agree. Loyalty is a good first step in the right direction, but managing your citizens and protecting your empire from *internal* strife should be a major point in Civ. Pity Civ 5 handled it as poorly as it did.
More generally, Religious Tenets should have much more comprehensive effects on your Civ and its Culture, especially in the first half of the game or so. Religion was, in many ways, the way people were identified and how they identified themselves within a society. There should be religious tenets, either choosable or, more likely, that generate as a result of other choices made, which reflect a society's openness to new people and things or internal cohesion - and possibly force actions on the government's (gamer's) part to maintain that cohesion or openness or lack of it.
For religion, I feel like Tenets should be less uniform, true. Each Orthodox Church (not refering to the buildings) has small differences, but they're still considered a part of the Eastern Orthodox Denomination of Christianity. In Civ though, all Eastern Orthodox Civs follow the same path blindly with no variation - in my language we have a great word for this: "
Eenheidsworst" - meaning:
Unity Sausage.
Religion is should not be a unity sausage. Players that are part of a religion should be able to make small tweaks to Tenets once converted - however, not too many - if they do, they're branded heretics and they scism away from their Mother religion. This basic principle is what gave us the Anglican Church (which, while
technically Protestant, is very different from other Protestant denominations such as Lutheranism and Calvinism), and caused the various denominations of Islam to resent each other. Scisms, religous integrity and internal religious strife should all be in the game, in some form.
Civ needs to shift away from their All Religions Can Be Identical nonsense for flavour reasons as well. It makes every religion feel milquetoast and samey, nothing more than a hollow shell containing the same skeleton, as some tenets are more powerful than others. The pool of Tenets should, to some extent be limited by which religion you found, mimicking that religion's development through history.
Maintaining player agency is just as important though. Sid Meier's Civilization is a game about creating your own Civilization within the confines set by the game and your map - but there should be some control by the players in how they shape their identity (and by association, their religion), either by adding new tenets to their Church or by reforming (tailoring) tenets to their Civilization's strengths and needs. Each religion should have a toolbox of Tenets available based on history, but the player should be able to pick amongst those based on need. A Civ's ability should, at least offer players
guidance towards what tenets their Civ would normally be gravitating towards.
But that's perhaps a discussion worthy of a different topic.
Making these things innate in a Civ is simple, but usually wrong. Arabia was open to all kinds of new people and ideas specifically because of religious and cultural practices at one time - and lost most of that under subsequent religious and cultural developments.
Counterpoint: You pick a leader from that time period and make it their ability - that would fit the zeitgeist of the time period you're trying to emulate.
Not only Jewish Temples, classical Greek temples served many of the functions of modern Banks - they made loans, and acted as safe depositories for coin and bullion, an Economic Attribute of the religious structure never, to my knowledge, acknowledged or modeled in games. Again, showing how variable the effects of Religious Tenets could and should be.
As someone who recently played through Assassin's Creed Odyssey, yes, the importance of religion in a society usually deemed secular by Civ Standards, was quite palpable. Maybe some Tenets should be
Civ specific instead of
Religion specific?
You would also have to distinguish between goods/Resources for Trade and those for personal use. Natural dyes were not, in game terms, resources of any kind, they were too universally available in one form or the other. Only the 'expensive stuff' should show up on the map or in any Resource system.
In the Clothing equation i posted, just leave the Enhancer slot blank. There's your natural dye, all accosted for.
BUT the basic trend in all resources should be the steady replacement of Natural Resources with manufactured or 'enhanced' Resources.
Making natural resources depletable would help,for starters.
Clothing wasn't a mass trade item - until Textile Mills could turn out masses of Cheap Clothing from Wool, Linen, or Cotton (mostly) at the beginning of the Industrial Era and in mass quantities both undercut every other clothing production in the world and also fueled the prosperity of Holland and England in the 18th century.
Clothing maybe wasn't but woven textiles were. When I say "Clothing" I mostly mean everything related to it, as splitting it up between types of cloth and types of apparel turns the game too much into Anno. (a great game in its own right, but it's not Civ) I've reworked resources plenty of time for my Civ7 vision and it's really easy to head to wn that rabbit hole if you're not careful.
Expanding a resource system into a craftable products and synthetic resource replacement systems as you mentioned is a dream, but also dipping into
XPac material. The
base game should probably just have the bare bones of the mechanics that you can build upon later. (Doesn't mean we can't think and spec and dream about it ourselves. We are CivFanatics, after all.
)