Thank you!
I'm glad to know you're not religious, but I know you like history. The Great Schism of 1054 was an event that interrupted mutual recognition between the Church of Rome (Western Christianity) and the Greek Church (Christianity of the Byzantine tradition). wikipedia
The Easter you have now is after the Church of Rome and the one that will be in Eastern Europe and Greece is after the Byzantine tradition. The date of Easter differs every year and is calculated according to the phases of the moon but also according to different calendars. (so I remember from older information and I'm not sure if I'm not wrong)
Yeah, they tended to make up a lot of things to suit whatever ends that each had in mind I guess, fair enough too considering the lack of any real facts to draw on.
Yes, I think so.