"If anything, an Orthodox believer would find it difficult to relate to her if she were ontologically different from the rest of us."
Now there's an exactly correct observation.
A few years back, my late father-in-law lay dying during Great Lent. My wife, a former Congregationalist, spent her evenings at church for the chanting of the Akathist. Sitting and standing there in tears, she poured out her heart to Panagia and those devotions were very comforting to her. I suspected I knew why, but I asked her anyway. She said that Panagia knew what it was to suffer and loose someone so very close to her so she could relate to where my wife was right then as a woman facing loss. My wife could never have felt that way about or have made such a connection to a "goddess".
In Orthodoxy, we are always made to feel as part of the Church in the most personal way. Heaven on earth is what Divine Liturgy is (if you participate in it), and as you say, we are always close to it. We kiss our icons as we would kiss the pictures of our dearest and most beloved family members. Our Church is more than a house of worship; it is our true home.