There were 5 patriarchs not 1.
All five were head of the Church and voted together. Not 1.
The virgin Mary went to Greece, Patmos and had a garden there and likley died there not rome, however that doesn't make the orthodox the head church. There is no headd church, the Church is governed by patriarchs and ruled by Christ. The Rcc has changed many things and lied about others. If you are rcc there are possibly lies you believe. For instance that Easter was last week as opposed to after Passover like the Bible says.
Also you have a crucifix, which Christ died and rose again he is no longer on the cross.
Rcc worships mary where orthodox honors and respects the virgin but worships only Christ.
The orthodox confesses sins but forgives comes from God and a God speaks through his priest and God forgives sin, not 5 hail Mary's and a man forgives you.