To answer the question, quite simply, Greek Orthodox is Eastern Orthodox.

Orthodox Christians know that when they enter the church, it is where heaven and earth meet.

Orthodoxy, which is the unchanged original teaching of Christ and the apostles, doesn't teach free will, it is free will. In the Eastern Orthodox Church (EOC) we are guided, not controlled. We are influenced, not told. We are illumined, transformed, and strengthened by our faith and not extinguished by doubt.

Traditions define who we are, what we do, and what we are a part of. They are like pieces of mosaic stain glass icon, unique individual manifestations, yet all forming and contributing to the whole picture.

I believe the simplest answer to your question would be that no one forces a non-believer to do anything unless the non-believer gives their permission.

The traditional or customary way is to stand through the whole church service. Some Eastern Orthodox Church jurisdictions have pews and others don't.