Major Plot hole: Part of the premise of this terrible movie is that everyone on the poster is Neo from the Matrix. They can all fight 10 opponents at a time because of their godly reflexes, agility and strength.
That's fine. But then it means that some things can't happen. One of them is to see Milady's cart being slowly hijacked by a flying ship and let Milady watch with terror the ground she is slowly leaving at the same pace as an old man standing up after hurting his back trying to dig his old porn DVDs from under the couch.
Major Plot hole: Queen Anne seems to be aware that Richelieu is scheming a complex conspiracy against her and the King - she indeed challenges the Cardinal on the fact that she knows about his vile intentions. And yet, when she realizes her diamonds have been stolen and are part of Richelieu's plan to frame her for adultery- she decides that speaking with Louis XIII about ANYTHING is not an option, and leaves her entire faith on the musketeers to bring her diamonds back.
Since the King is deeply in love with her, since he is a good guy, and since she seems to have a lot of control over him, it is rather silly to see the Queen opt out of trying to explain the situation to him.
Unaddressed Issue: D'Artagnan's father shares an emotional scene at the beginning of the movie with his son. He trains one last time with him and gives him his sword that is said to be passed on from father to son for generations. So when D'artagnan sticks his sharpy heritage into his nemesis's chest on Notre Dame's rooftop, he doesn't seem to care about it anymore and discards it completely as it falls with Rochefort to the ground. What a dick!