Here's one aspect I don't understand, and maybe you can help me: does the Orthodox Church also have (distinct from divorce) such a thing as annulment?
In other words, if something was truly defective about the attempted marriage from the very beginning --- say, they just went through with the wedding to affect the groom's immigration status, with the intention of divorcing thereafter; or they lied to the priest about their age and were in fact underage and personally immature as well; or the wife had no intention of ever having children, but secretly took morning-after pills, deceiving her husband --- is it also possible to get an annulment in the Orthodx Church? Meaning, an investigation and a declaration of nullity, ruling that this was never a truly a sacramental marriage?
pinging myself to respond latter, and to get other Orthodox thoughts on this.
"--- is it also possible to get an annulment in the Orthodx Church? Meaning, an investigation and a declaration of nullity, ruling that this was never a truly a sacramental marriage?"
Kolokotronis would be more up on the canonical points, I think. But in general I still think that people in the situations you mention would get an ecclesiastical divorce, not an annulment.
Since for us a marriage is something that God does through the Church, without contractual elements, that would be the same as saying that someone who walked up for communion who hadn't been baptized and "slipped through" didn't receive the Body and Blood of Christ, since his reception of communion was grossly defective.
Even in the situations mentioned by you, the people were still married by the Church. One can't pretend that they stood in front of a priest wearing robes, had their clothing saturated with the smell of incense, and processed while "Rejoice, O Isaiah..." was being sung -- and had no idea that they were being married by the Church.
I would think that only cases of gross coercion would fit the bill for anullment for us.