You will also note that I have criticized some behavior of the Patriarchate of Rome prior to the schism (with regard to services in the vernacular).
I honestly believe that you overestimate the changes brought on by the temporally and secularly more favorable circumstances for the Church after the Peace of Constantine. I already enumerated features commonly ascribed to the Church's good relations with the Empire (and condemned) by protestants who regard a hypothesized "pure" early Church as their model for reform, features which in fact predated the Peace of Constantine.
The only two changes of any ecclesiological or soteriological import resulting from the Peace of Constantine were first the fact that the Emperors, desiring peace in the Church, from time to time called councils to settle disputes. The councils in which imperial meddling carried the day (e.g. the "Robber Council" in which the heresiarch Dioscorus had detachments of troops a his disposal, and the iconoclastic synods) were invariable rejected by the Church.
And second, the rise of monasticism, by which Christians sought another means of radically rejecting the world to follow Christ, martyrdom no longer being generally available. I should observe that in Orthodox practice, monasticism does not generally involve erecting a wall against the world, but seeking to remove oneself from its distractions for the purpose of prayer. We thus have the fact, curious to Westerners, that large portions of Siberia and Alaska were converted by monks (in Alaska the Aleuts attribute their conversion to St. Herman, who lived as a hermit on an island).