1. Dual screen functionality is not fully implemented, but will be a free update at some point in the future, it will not be locked.
2. When dual display is implmented this will be possible, but not at this time.
3. The streetdeck hardware enabler will be available at the mp3car for purchase whenever it it finished.
4. Yes you can use km.
5. StreetDeck is currently only available in english, you can not change the language yourself.