Paying attention to what is and is not in the Scriptures is adding to the Scriptures? Is this Rome’s logic?
No. The doctrines of sola scriptura and sola fide are adding to scripture, outside scripture. Taking your personal interpretation as authoritative is adding. These are not in scripture, contrary to scripture.
Scriptures are only an incomplete reflection of the Word. They are important only in that they give testimony to God. Jesus is found in the Eucharist and Grace in the Sacraments.
"You search the scriptures, because you think that in them you have eternal life; and it is they that bear witness to me; yet you refuse to come to me that you may have life." - - John 5:39-40