Decem,
The catechism isn't infallible. It can't be looked at as a "interpretation" of a council. That's not it's purpose and you're using this tool for the wrong job.
Secondly, to get a clear view of this catechism, we'd have to go back to the original latin. As has been proven many times, once things get "translated" from latin into vernacular languages, the opportunity for corruption/liberalism is great. One only has to use the "for many (latin)" and "for all (english)" heresy as an example. But such mis-translations/additions also happened way back in the 1600s.
Even then, no one is obligated to read, own or believe a catechism. I've never read Trent's catechism and I don't plan to. And this won't affect my salvation at all. Which means, a catechism isn't "doctrinal" (if it was, i'd have to give unquestionable assent to it) nor is it as important as you make it out to be.