You haven't proven anything other than a zealous opposition to anything "Oriental" and anything that runs counter to your dim view on "The West", and you accuse me of being motivated by feelings.
There's abundance of evidence, examples, and just general academic consensus that Byzantium and the cultures it influenced are as European as it's geographically western counterparts. Your schema on the other hand is literally out of the Middle Ages.
No, Byzantine cultural influence was always limited in the Western Christian World. That's why renaissance arts were not really influenced by Byzantine Empire. The Western Roman architecture influenced it, which was very different from the Asian influenced post-classical era Byzantine arts.
I don't disagree, but that same elementary knowledge comes with the caveat that much of the knowledge that propelled the Renaissance came from Byzantium in one capacity or another, because Western Europe already had a demand for Byzantine fashions for centuries. Aachen Palace was designed by Byzantines. Carolingian court attire and functions modeled those of Constantinople. Byzantine nobles and even imperial members of the family like Anne Komnene regularly intermarried in with western dynasties and brought their education and custom with them, such as using utensils at the dinner table, or regularly bathing.
Wrong. Byzantine material culture (production tools, buildings and housing of the population , the clothes foods, artistic taste) remained closer to near-eastern and North African countries than to Western Christian Western European countries. Even the average Byzantine households of common people were resembled to Near Eastern and North African cities. Even their cloting was very similar to Near Eastern and North African clothing, the only difference was the lack or Turban in Byzantine Empire.
Reality is that "East and West" aren't as opposed or as defined as you think they are. Aside from religion the line between them wasn't that sharp and that one division often evaporated in the face of actual threats like the Saracens, Huns, and Mongols.
The differences were sharp in development of institutions and politics, in societal development, artistic development (architecture, sculpture painting visual arts) clothes and fashion, in science and technology, in economic development. Orthodox world was a different civilization.
Saying that Slavs share a common history and that they're part of the European family isn't a pan-Nationalist agenda. That's just fact. Slavs are close relatives to Germans, Baltics, and Nordics, and they have more history with other European powers than Asian ones.
Just try to say for Czech or Pole, that they are have similar culture as Russians or Ukrainians, they will interpret it as a brutal provocation (And they have right in this case)
"Slavs are close relatives to Germans, Baltics, and Nordics"
Again you lumped together all slavic speaking countries. Czech Poles had close cultural relationship with Germans, but ukrainians and Russian people hadn't. Some commercial relationship did not bring automatically distincts culture closer. Otherwise if we follow your false logic, the the big colonial Empires Like France UK and smaller countries like benelux states would have been African or Asian culture.
I too am an atheist with a Protestant background, but I know enough about Orthodoxy that it's not somehow "Eastern".
No, I don't believe it. You are some Russian descendent Orthodox beliver who was born in the USA. Otherwise , why would you propagate the history fantasy of an average Russian skinhead?
Culturally, theologically, and historically it's more in common with Catholicism than most Protestant sects, especially since there's been a gradual warming reconciliatory relationship between the Vatican and the Ecumenical Patriarchy since near the end of the Cold War. The division between the two churches have been almost always politcally motivated.
Protestantism is closer to Catholicism (even in theological aspects) than Orthodoxy. No wonder, since Protestantism developed from Catholicism. Read this article:
Western Christianity - Wikipedia
Again, saying that Slavs have a common heritage isn't nationalist tripe but a statement of fact. Slavs share certain linguistic and cultural elements that predate the religious and nationalistic differences. That make them Slavs; same for any other European ethnolinguistic population.
This similarity exist only in your mind. There is paractically close to zero relationship of pre-christian era culture in Slavic and Germanic speaking countries. Slavic remained nothing more than a linguistic group. The weakened chunks of pre-christian era "common Slavic" culture remained in some degree only until the high middle-ages.