There are however non-biblical teachings in the "disputed book", which really aren't disputed by the Hebrews or the early church. It is the RCC that continues to purport these are inspired Scripture.
I agree. This topic has been posted on FR a number of times and it is pretty regularly brought up whenever there's an ongoing Cath vs. Prot argument - it is some people's imagined "trump card".
What I have yet to get an answer to, and I've asked it several times, is what are their "favorite" passages from any of those books and what doctrines are found there that cannot be found anywhere in the undisputed books of the Bible. I have concluded that the real reason for the defense of these books is because it became an issue during the Council of Trent and some conclude - somehow - that this is enough evidence to prove the Roman Catholic church is superior to all other churches. Personally, I don't see the point. I think many Catholics have no idea what these books are about, who wrote them, why they were included while others were not even though they were in the Septuagint or that the Septuagint contained several OTHER books that were left out of the Trent canon. Appealing to their presence in the LXX is not really an adequate argument for why ALL Christians must accept them as inspired Scripture.