Socialism

First of all, again, I want to stress that what's more important is the class outlook, not the location. Urban vs. Rural living has some impact, but this is subordinate to the class makeup of cities vs. the countryside.

Either way, cities are not "individualist." I don't know what you mean by individualism if you believe them to be individualist, and individualism is not associated with secularism. The proletariat is collectivist in that their path to liberation is in collectivizing the means of production, genuine individualists are largely small business owners and self-employed people that seek to retain their autonomy.

As for religion and the ruling class, lords and masters generally claimed that they deserved to be there by divine right. Religious values also generally pushed ideas like glorifying the impoverished, in other words trying to placate the people and prevent them from looking at the actual material reasons why they were being impoverished while the masters and feudal lords were wealthy.

As for a book explaining European colonialism and the slave trade, I recommend highly Walter Rodney's How Europe Underdeveloped Africa. It's solid gold, and Rodney was assassinated shortly after its writing.

I don't know what you mean by "fascism as a concept exists outside of the communist framework." Communist analysis is not something we impose upon the world, but is the way we analyze it. I have no idea what you believe fascism to be. As for Russia, it was imperialist under the Tsar, then the Soviets liberated the Tsar's colonies. The modern Russian Federation isn't imperialist, it has no colonies nor neocolonies and has been kept outside of the international financial oligarchy by the west. They tried to join NATO a few decades ago and join the west in plundering the world, but the west shut them out as they wished to recolonize Russia, and as such Russia had no colonies to inherit from the soviets (who were deliberately anti-colonial) and no colonies to gain.

As for capitalism and growth, that's not inherently a problem. The problems are that capitalism is focused on profit, and that it needs growth to survive, which leads to imperialism once domestic markets are saturated. Here's Marx on the subject:

The proletariat will use its political supremacy to wrest, by degree, all capital from the bourgeoisie, to centralize all instruments of production in the hands of the State, i.e., of the proletariat organized as the ruling class; and to increase the total productive forces as rapidly as possible.

As for your questions on culture and linguistics becoming homogenous, this is actually one of the most important conversations in Marxism, known as the "national question." Right now I am trying to focus on it in my own studies as it isn't something definitively answered like other questions have been. As such, I cannot give a satisfactory answer to this question as it's still ongoing, and there are those that believe either path. Perhaps in the far, far future this will all come into one "human" identity, but at the present moment indigenous rights are critical, as national liberation and autonomy is a prerequisite for socialism to begin in the first place.

As for differences in how conservative social views are frequently uneven, I'd have to have specific examples. The better way to frame it though is not as conservativism as a deliberate choice, but through which avenues is progress happening more or less rapidly. In general, West Asia is a hot topic of imperialism as its where the petro-dollar is solidified, and as such much conflict is going on. Conflict slows social progress, stability helps accelerate it.

As for individual traits, for them to have an impact in distinguishing nations, they'd have to be based on ethnicity, rather than evenly randomly distributed. That's why I said this is more race theory, individuals do have different traits but this is not understood to be on the basis of "race."