Hi Ron,
You might have gathered from recent posts that I only just got the P5000 very recently. I haven't had much time yet to learn much beyond the basics about the device.
To answer your two questions:
(1) I am pretty certain there is no charging from USB, but I could be wrong.
(2) I seem to remember the manual says you can transfer to another HD.
I suggest you download the full manual from the Epson (Europe) website... that should help answer these and many other questions you may have.
Sorry I can't be more helpful just now... I'm stuck in China on a business trip and only have slow internet access.
Mark