If the religion to be represented is Zoroastrianism, the fire-holder could look more like this (coinciding with the "three-stepped top and base" description given in https://www.iranicaonline.org/articles/achaemenid-religion):   Sadly, it's not really known how Achaemenid temples looked like. Zoroastrian fire-holders seemed to be in the open, while, regarding some towers that were previously thought as temples, "the hypothesis positing a religious function for the tower-temples in the Urartian period is generally accepted, despite certain differences in the architectural environment of several of them; by contrast, the function of the two Achaemenid towers remains totally enigmatic. The only hypothesis that is not a matter of contention, as a result of both environment and architecture, is that of a deposit for objects, very probably of a royal and not a religious nature", from Studies on the Architecture and Archaeology of the Achaemenid Empire, by R. Dan. It is also thought that other religions were influential.

I be kinda sad

Yeah. I'm not a fan of the different fords that at least I can't differentiate by sight. On "Rivers" pedestrians can cross while ships can't, on "Gualdaquivir River" all units can.   This ("Mediterranean") is not oceanic enough?

A proposed upgrade for Han houses: The Tower House   +5 population bonus +5 vision range +1 projectile (short ranged attack added)

Yep! "Slave Trade" is another one of their techs/team bonuses: Effect: Allied Slaves -50% train time as long as the Scythians maintain a Market.