Yes it is. And you are correct - since it is the word of God, none of us have the authority to definitively answer that sort of thing.
However, God gave the authority if not to decide, then at least to discern, the meaning of Scripture to His Church.
But in many cases the Church hasn’t definitively said anything (is the garden of Eden literal or not?). In these cases, some of us enjoy thinking about it and trying to figure it out for ourselves, but to do so properly requires that 1) we recognize that no matter how good our arguments seem to us, unless and until the Church adopts are position it is perfectly ok for Catholics to disagree with us, and 2) we cannot take our own theories so seriously as to think believing as we do gives some new information that is necessary for salvation or somesuch.
That is, for the most part, ideally, and among Catholics, such debating is simply an intellectual exercise and/or an attempt to bring ourselves closer to God. None of the disagreements among Catholics can be essential, because the essential things are already known and taught by the Church.