Why would it be up to the Pope? The Pope is nothing more than the Patriarch of the Roman/Latin Church. He is not supreme. Papal supremacy is an error. It is a perversion of primacy. The Eastern Catholic Churches need to assert themselves and remind Rome that her Pope is the first "among equals" and not the supreme overlord standing in for God Himself.
Christ is in our midst!!
Easy. Let's not get our blood pressure up. The reality of the Catholic Communion, of which the Eastern Catholic Churches are part, is that Vatican I defined our reality differently. That said, Vatican I is a stumbling block to all those outside our Catholic Communion when it comes to discussions of ecumenical dialogues and discussions of renewed communion of all the Churches and ecclesial communities which preach Jesus Christ. That is reality; that is our take on the truth; that is our take on Christ's instruction to St Peter. The Pope approves all of our canon law collections. He exercises the right to change or abrogate any single law. He is the only one who is not required to tender his resignation at the age of 75; he accepts all the resignations. No one may question his moves. That is reality.
Your historical assertion about who left who is a matter of who is writing history.
There is no perfect way to organize Church life. The Catholic system rubs some the wrong way, but there is a final authority to sort things out. In Protestantism, when things don't' work out, people separate and set up new organizations. In Orthodoxy, as we are seeing to our great dismay, we have a current de facto schism going on and it seems there is no resolution. (BTW, I am greatly saddened by the current developments because I firmly believe that we need what Orthodoxy has to offer in terms of how the Faith is lived out.)
I personally have come to see the Office of Peter as exercised in the Catholic Church as necessary, though I may harbor some of the things you mention. We have Catholic bishops who do not uphold the faith, just as other Churches and ecclesial communities do. But we do have a place where the buck stops and we can know what is definitely to be held as the Faith. The Catechism of the Catholic Church is a great example of this. While there is a currently a great argument over Catholic politicians flouting the issue of the Church's teachings in their public statements and lives, we can know for certain what is and what is not the truth in the matter, especially about who should and who should not be receiving the Eucharist.
Ultimately it comes down to your and my living out the Fatih and the example we give. I am not responsible for the celestial discussions of who is the boss/who is at the top of the pile or the justification of it all. I am responsible for the people I serve and the example I give, the words I speak and the people I either edify or scandalize. When I meet the Lord, this is what He will ask, not my arguments about titles or organizational charts. He will ask if I have been the first to be a peacemaker, the first to reconcile, the first to offer forgiveness to those who have wronged me. He will ask if I have been His eyes to seek out, His ears to listen, His voice to encourage and to pray, His hands to work, His arms to embrace, His legs to carry me where He needs His Presence to be. Christ has no Presence here right now except the presence I give and the image of Him that I am called to be by my Baptism.