So, in soon to be Saint Pope Paul VI decree on the Catholic Churches of the Eastern Rite, Oreintalium Eclesiarium, he states in the opening sentence, “The Catholic Church holds in high esteem the institutions, liturgical rites, ecclesiastical traditions and the established standards of the Christian life of the Eastern Churches, for in them, distinguished as they are for their venerable antiquity, there remains conspicuous the tradition that has been handed down from the Apostles through the Fathers (1) and that forms part of the divinely revealed and undivided heritage of the universal Church.” So not only liturgy but also their “ecclesiastical traditions.” Ecclesiastical traditions include not only liturgy but discipline, devotions and theology.
The document goes on to say, “The Sacred Council, therefore, not only accords to this ecclesiastical and spiritual heritage the high regard which is its due and rightful praise, but also unhesitatingly looks on it as the heritage of the universal Church. For this reason it solemnly declares that the Churches of the East, as much as those of the West, have a full right and are in duty bound to rule themselves, each in accordance with its own established disciplines, since all these are praiseworthy by reason of their venerable antiquity, more harmonious with the character of their faithful and more suited to the promotion of the good of souls.”
The documents may not address articles of faith that are binding to all Catholics, but they do state that we as Eastern Catholics have a duty to continue practicing our spiritual heritage (liturgy, theology, discipline and so forth).
This is very, very simplified but when a good friend of mine, Roman Catholic, asked me what the differences were in theology I explained it like this: the Latin Church teaches that 4+3=7, the Byzantine Churches teach that 5+2=7 and the Oriental Churches teach that 6+1=7. All equal 7, just the way in which 7 is made that is different. Now, there is way more to it than that (Immaculate Conception, Purgatory etc.), but I think it’s a good example.
There are many on this forum who are much smarter than I so if I have something wrong, please correct me!