Question: If, as Odin says, Mjolnir was never the source of Thor's power, then how come that "Whosoever holds this hammer, if he be worthy, shall possess the power of Thor"?
Answer:If other people are worthy, they can gain the power of Thor (this is something that has happened in the comics), but Thor can muster that power alone. In his case, the hammer simply allows him to focus his powers.
How come then that in the first movie when Odin wants to remove Thor's power he "confiscates" Mjolnir? If Thor's power is intrinsically inside him, how could Odin remove it? Then, he reacquire those powers only after holding Mjolnir again, which implies Thor's powers come from Mjolnir. This is poorly explained in the movies.
"Poorly explained" doesn't make it a mistake. Odin suppressed Thor's innate powers and removed the hammer both symbolically and to prevent Thor from using it to reacquire his powers.
Answer: If other people are worthy, they can gain the power of Thor (this is something that has happened in the comics), but Thor can muster that power alone. In his case, the hammer simply allows him to focus his powers.
How come then that in the first movie when Odin wants to remove Thor's power he "confiscates" Mjolnir? If Thor's power is intrinsically inside him, how could Odin remove it? Then, he reacquire those powers only after holding Mjolnir again, which implies Thor's powers come from Mjolnir. This is poorly explained in the movies.
Epigenis
"Poorly explained" doesn't make it a mistake. Odin suppressed Thor's innate powers and removed the hammer both symbolically and to prevent Thor from using it to reacquire his powers.