Well, there's nothing there about "necessary", as if you have to know it in order to attain salvation. That's a Protestant idea, that there exists information without which one cannot be saved.

I'm confused. The part of the Catholic "offical teaching" stated: "the books of Scripture firmly, faithfully, and without error teach that truth which God, for the sake of our salvation, wished to see confided to the Sacred Scriptures."
Isn't what is for the "sake of our salvation" also not
necessary for our salvation? If it is a "truth" for the sake of our salvation, if we reject that truth, are we not also rejecting the salvation? If I have misunderstood, please explain.
In the Anglican tradition (which is admittedly closer to the Catholic), what is stated that nothing
not in scripture can be declared "necessary" to our salvation. For instance, if someone were to declare that opposition to abortion was necessary to salvation, they would have to demonstrate that by scripture. It originally came about because the Catholic Church, ironically, was declaring (in Luther's time) that certain practices (such as penance and indulgence) not mentioned in scripture were necessary for salvation.
I presume that you mean YEC's. I'm a creationist myself, but I'm not a YEC.
I'd say that creation did happen as stated in Genesis 1-3, but that what's stated wasn't intended to be a science text.
Sorry, but you cannot state that "creation did happen as stated in Genesis 1-3 but then state that it is not a science text. That is contradictory.
How creation happened
is science! You are stating that the earth existed prior to the sun and stars because that is
how it happens in Genesis 1. You are saying either 1) God spoke men and women into existence (Genesis 1) or 2) God formed a man from dust and then a woman from the man's rib (Genesis 2) because both are
how it happens.
If you are going to hold the position below:
Like when my kids first asked about the origin of babies, my answer was true but wasn't intended to detail the bilogical processes. More important was the bit about love, relationship and their dignity and importance as human beings.
So, did you or did you not give an alternative
how babies happen? You may not have given the details of sex, but did you say that babies are born (come out of) mommy? Or did you say the stork brought them? Both of those are
how it happens. The first lacks all the details but is essentially accurate. The second is not accurate or truthful.
The question is whether Genesis 1-3 is accurate about
how it happened. It can (and I believe, is) true about the Who and why of creation, but is not accurate about the "how". Creationism is about the "how". Since I don't think Genesis 1-3 gives the true "how", I am a theistic evolutionist. Evolution (science) being the
how it happened.
So, is "creation did
happen as stated in Genesis 1-3" a truth for the sake of our salvation?