1. It's about one metre long (39 inches)
2. Yes, you could just use a USB extender cable
3. Yes it has a usb at one end that goes into the wall unit
4. Yes you can use the iPad while it is charging from the wall
5. Yes you can use it while it is plugged into the computer (not while it is syncing with iTunes but you can cancel that at any time)
6. I use iTunes to transfer ePubs for use with iBooks.
You can also send epub files to Stanza using dropbox (with the free dropbox app) or use calibre. See
http://www.lexcycle.com/faq/how_to_g..._stanza_iphone for more details.