Catholics canonized these extra-biblical books (just as they canonized their own traditions)
Actually, the Catholic cannon is smaller than several Orthodox ones. There is a lot of issues to be laid at the feet of Catholics, but adding uninspired books to scripture isn't one of them.
The Bible can be translated perfectly because that is the doctrine of preservation: if we cannot authoritatively translate some word in the Bible, then God has not preserved it, and part is lost
Did scripture teach you that doctrine? It's just that, a human construct. It's not lost, we still have the manuscripts passed down. Translation isn't a perfect science, esp. over the passage of time. Especially since the end language is a moving target. If any language had a shot at getting a perfect translation it was English, with our multitude of attempts and abundance of resources and motive. Haven't seen one yet that even came close to accomplishing it.
But it doesn't matter because we have enough info to have confidence in the message and the doctrines they teach. If you work with a reasonably good translation you have to get a ways down the road to faith before translation differences have a measurable impact on decisions.