1) yes. AFAIK
2) yes.
I don't have a paperwhite but in answer to your points generally Amazon have only released one "complete" (which is arguably very useful for support) update.
scratch that... I just went and checked... they are full updates - (thanks harry.)
There are a few threads containing details of holding back the tide and personal privacy, but in the main Amazon have played nice.
EDIT: Ixtab provides
some method of carrying across the jailbreak evidently. For full updates
Hope that helps (THANKS HARRY)