I cannot answer those three questions of yours, but I can share a bit of my experience with the JE100 concerning wifi.
- the wifi dongle is not very convenience to use, you have a 5" extension cord with a usb stick attached hanging from the unit while using it, very annoying.
- Battery consumption is, more or less, doubled when wifi is on. Your usable battery life would reduced to about 1 hour or less.
- If you plan to surf the web, forget it. Web page(with graphics) display on JE100 is very S L O W W W.....

This is due to limitation of the hardware.
But apart from this I am very happy with my JE100...
Hope this help.