St Jerome stated that to be ignorant of Scripture is to be ignorant of Christ.
Catholics are encouraged to read and study the scriptures, and that includes interpreting them. However, our interpretations must be guided by the Church, whose book “the Bible” is. The Scriptures are a compilation of christian writings [the New Testament] and the hebrew writings from which Christianity has its roots [what we call the Old Testament and perhaps more correctly referred to as the Hebrew Texts].
Perhaps you can consider it this way. The New Testament writings were written by a faith community for the faith community. When all of the early christian writings were considered, the Church judged the authenticity and thruths contained therein, accepted some for the canon [as illutrating the origins and core beliefs], treasured others but did not consider them a necessary for inclusion into / or a part of the canon [like the writings of the Early Church Fathers], and rejected others as heretical [like the Gospel of Thomas].
So catholics must always guard their personal interpretations against the teachings of the church. If your private interpretation does not counter an official teaching great. If for example; all of a sudden you decide that the Gospel of Mark is heretical or that because Jesus called himself the ‘son of man’ he is therefore not God then you should refrain from biblical ‘interpretation’.
Limbo was never a ‘doctrine’ but a theological construct. It was taught, some would say overly so, and many people began to think of it as a doctrine. We cannot answer every ‘mystery’ and some things are known only to God. Theologians love to consider things like “How many angels can dance on the head of a pin” They may come up with an answer and support it but in reality only God knows for sure…limbo was like that.
So what happens to un-baptized children or the righteous Jews? Only God knows as it is God’s perview…God alone determines the fate of all mankind. It is God who decides, not the Church, not me and not you. Now the church is given a message to share with the world…Follow Christ, be baptized, belief in the Trinity, etc. That is what has been entrusted to the Church to teach. The Church cannot teach that you can be saved by “believing in Trees” Would that mean that a pewrson who worshipped “Trees” would go to hell? Only God knows.