Hi  marcustacitus :) 

Thank you for improving OSM data in Greece :) I can tell you a cheat way to find the name of a church (if you can go inside): once you step into the church, you'll see opposite you the gate of the "templon" (the wooden surface that separates the sanctuary from the rest of the church). The second icon to the left of that gate, displays the name of the saint that the church is dedicated to, and I would say in 99% of the cases, it is the name of the church. E.g. if the second icon to the left of the templon gate is "Agia Anna", then the church is called "Agia Anna". 

Fun fact: The icon exactly to the left of the templon gate is always Virgin Mary and the icon exactly to the right of the templon gate is of Christ.

Thanks again for mapping Greece :)