Just as an aside, the Eastern Church is "an" or "the" early Church, depending on your point of view. So what we have taught about marriage and clergy isn't a departure from anything, it is a component of the consensus on the issue. Put rather clumsily we emphasize a different side of the same coin on the issue of clerical marriage.
You are correct about that it is about ordaining the married and not marriage of the ordained. Both the East and the West would not allow for clerical marriage following ordination. In the East we simply believe that there is no Apostolic warrant for MANDATORY celibacy for clergy and this is where we differ from the West except in the case of Bishops (who are drawn from the ranks of monastics or celibate clergy).
I'm not so sure about the West being somehow less hindered from the state and able to develop its thought more in line with the genius of Christianity. That's a nice partisan statement but its basically unproveable. I think it would be better to say that both the West and the East have had periods where they were more or less influenced by the machinations of the state.
Since we both agree that celibacy is a matter of discipline and not dogma it is perfectly okay to revisit the issue if the Roman Church wishes to. I think they should and they have the model of the Eastern Church to give them a viable, ancient, and apostolic model if they so choose.
Not really.
It's a fact that the Emperors in the East were far more effective in governing secular and temporal affairs in Constantinople up till the atrocity of 1453, whereas in the West the Emperors were usually ineffective absentees who spent the bulk of their time in Milan rather than Rome. By the 500s the emperors in the West were gone and there was a complete power vacuum with various localized lordlings in dozens of shifting alliances.
One sign that the Empire in the West was weak or nonexistent was the absolute lack of claimants to the throne after the abdication of Romulus Augustus in 476 - who just gave up on the office of Emperor rather than defend himself militarily.
The Roman nobility petitioned the Eastern Emperor to appoint a replacement, but he refused because the Romans had overthrown two of his previous choices.
From 395 to 771 (376 years!) there was no effective ruler in the West and from 476 to 800 there was no nominal Emperor.
For about 40 years (775-815) there was centralized political leadership, but by 850 the West was in political chaos again and wouldn't see any true stability until around 1250 when France had strong kings and Germany had strong Emperors again.
So from about 400-1250 there was no effective political center in Europe except for the brief Golden Age of Charlemagne's reign.
And even then, it was 250 years of shifting alliances around a French-German rivalry followed by the Reformation and yet another outbreak of political chaos.
The Eastern Emperors and the Ecumenical Patriarchs enjoyed a close, symbiotic relationship for centuries with only brief episodes of animosity - the Popes experienced the exact opposite state of affairs.