[Worseacar]

Welcome, Mark!

A few threads which touched on the issues you mention are:

Catholic curious about filique
Bede and filioque
The nature of Roman Catholic heterodoxy
Pre-schism popes: 'universal rulers' of the Orthodox Church?
Peter, prince of the apostles, and the hierarchical structure of the church
Orthodox communion with Rome

I'm sure there are many more, but that's all I have time to look up right now. Hopefully they'll be of some profit!

In Christ,
Michael