Even if one does not believe that John Paul II is an Anti-Pope, it is still a bad idea to read his books. John Paul II was a phenomenologist and a believer in the Hegelian dialectic.
For the phenomenologist, "truth" is not an objective reality defined by God, but rather something that is defined by the subjective consciousness of the observer. As such, it is an incredibly dangerous idea, and while not formally heretical is certainly opposed to Catholic philosophy.
It's not "formally" heretical because all of the bishops are heretical also, so who is going to say it's heretical? Everything that you wrote above also applies to Benedict XVI, whom the accordistas are wanting to "go home to".
If after I've explained all of the above (what you wrote and I added), if anyone insists on reading JPII or B16, , I just let them do it. At the end of paying for the book and reading it, they'll find out that they are more confused that when they started, and poorer.
For those who are not really Catholics, the main reason not to read JPII or B16 is because it's a waste of time, they don't say anything clearly
. I think God has something to do with that.