What's the difference? Aren't catholics and all those "other" related sects really all the same I? think you're splitting hairs here.
NRx, you're a N00bie and probably don't know me, but I'm a relentlessly schoolmarmish old Freepageezer now sick in the rehab hospital, trying to feebly toss out baubles of wisdom as I can. I take it you're a Concerned Catholic? Sincere welcomes from all of us.
On Gregory being a member of the Armenian (Oriental Orthodox) Church, keep in mind that nobody is personally a heretic unless they have personally embraced a heresy, and have clung to it despite due warning and correction. And the same goes for schismatics: unless you personally split the Church, or knowingly joined the Split-the-Church party, you are not personally guilty of schism.
As far as I know, all of the Orthodox Churches (Chalcedonian Eastern and Oriental) have valid lines of Apostolic Succession, therefore have valid priests and bishops, valid liturgy, valid sacraments, etc.
The main divisions, as I see it, are political/cultural/lingistic, not at the level of faith and morals.
The academic theologians will wrangle forever about the difference between monophysitism, miaphysitism, and dyophysitism, but my own view is that these issues are unlikely to come up at the Last Judgement (cf Matthew 25).
All of Gregory of Narek's writings can be found online. Here's a sampler (LINK)
Let's join him in prayer. Let's honor this honorable, God-pleasing man.