Can you still be considered Roman Catholic if you hold this belief?
That would be considered a heterodox belief, so you couldn’t in good faith call yourself Catholic if that’s what you believed.
Ecumenical documents like the Chieti statement are non dogmatic Ecumenical pronouncements.
Dogmatic documents from Ecumenical Councils like Vatican I’s “Pastor Aeternus” and Vatican II’s “Lumen Gentium” and “Christus Dominus” hold infinitely more weight than any documents coming from Ecumenical dialogues. The dogmatic pronouncements from Ecumenical councils are dogmatic and infallible, whereas the ecumenical dialogue documents are fallible and mainly pastoral.
You COULD however remain a Catholic in good faith while hoping and praying that the dogmas of papal infallibility and supremacy be restated or reformulated in a more acceptable way for the Easterners. You could also hope the Catholic Church move to a more collegial ecclesiology as opposed to the more papal ecclesiology. Canon Law and certain canons in it could also be reformed, and the Roman curia could be changed in its function with regard to the East as well.
Something which I personally pray and hope for, is for Rome to promulgate a document explaining the theology behind Filioque and why it’s orthodox, and then permanently mandating that in all Liturgical celebrations in any Rite East or West, the Filioque is NOT to be recited.
I also hope and pray for the Roman Church to reinstate a permanent married Roman priesthood.
I also hope and pray for Rome to go back to administering Chrismation and Communion together with Baptism even to infants, and to stress that Baptism by triple immersion is the ideal form to be utilized whenever possible.
I also hope and pray for a reform of the Roman liturgical Rites so as to have them recover much of what was excised in the post-VII liturgical reforms.