Your catechism is merely a commentary on a few of the scriptures and a very poor one at that...
You ought to read some of the commentaries out there that cover all of scripture...
It does provide many references, however, this does not mean they are actually defining a verse as teaching what they invoke it for, for as in the case of purgatory, references ( Cf. 1 Cor 3:15; 1 Pet 1:7. 2 Macc 12:46; Job 1:5) often only refer to an aspect of what they seek to support, not that the verses actually refer to what they teach.
And which can be acceptable in support of a teaching based on the weight of Scriptural warrant, but assurance of Rome’s doctrine is not dependent upon this, but rests upon the premise of Rome’s assured infallibility, with full assent of faith being required for infallible decrees.