1) What does that MEAN?
I believe you attempted to answer this question in good faith, however all I read was a lot more gobblety gook. Sorry. And although you may think otherwise, I don't think it is because I'm just not bright enough to understand it.
The other 2 questions...
2)Do you really think that this is clear? and
3)Do you really believe that clarifies Traditional Catholic doctrine?
I don't think you answered either of those at all. The world has answered though. They think John Paul II has changed Church teaching regarding salvation and the necessity of belonging to the Catholic Church. They know what the Church has always taught, and they hated the Church for it. They hear (heard) John Paul II say something very different, whether he meant to or not, and they are applauding him for it.
And I don't buy your analogy either.
"It follows that these separated Churches and Communities, though we believe that they suffer from defects, have by no means been deprived of significance and value in the mystery of salvation. For the Spirit of Christ has not refrained from using them as means of salvation which derive their efficacy from the very fullness of grace and truth entrusted to the Catholic Church".12
This part of your analogy may fit:
"True, the guy over there stole some of my beat-up display models,"
but this part doesn't:
"I doubt that the cops will let you get away with buying one - you'll have to give me back my car, and lose your money to him besides."
"For the Spirit of Christ has not refrained from using them as means of salvation"
Defects and all, other "churches" are a means of salvation. Why be Catholic? The means of salvation can be attained in other "churches". There is nothing in that statement that says otherwise. The rest of your analogy may apply to what you wish he had written, not to what he actually wrote.
This Sacred Council wishes to turn its attention firstly to the Catholic faithful. Basing itself upon Sacred Scripture and Tradition, it teaches that the Church, now sojourning on earth as an exile, is necessary for salvation. Christ, present to us in His Body, which is the Church, is the one Mediator and the unique way of salvation. In explicit terms He Himself affirmed the necessity of faith and baptism(124) and thereby affirmed also the necessity of the Church, for through baptism as through a door men enter the Church. Whosoever, therefore, knowing that the Catholic Church was made necessary by Christ, would refuse to enter or to remain in it, could not be saved. (LG 14)
Looks like a powerful reason to me - and it's quoted in the CCC too (I don't think that the "means of salvation" bit about the schismatics is in there, by the way).
Q2: no Q3: it's the same.
They think John Paul II has changed Church teaching regarding salvation and the necessity of belonging to the Catholic Church.
That's unfortunate.