1: Simple answer is (YES) but you won't know the revs, miles, temp, fuel and of course the speed.
2: No it won't, it is all stored on the unit it self.
Mook doesn't do the changing service thats why i went corporate on here. I do change the smts and all the facia which you can buy off mook, the turn around normally takes 3 days as it takes 1 day to send and recive, 1 evening/night to do the dials and i send them off the next day. Some people have used sat navs to check the speed for the 3 days it takes. I can also recalibrate it to the tom tom speed but i do keep it a 1mph off so you don't get in trouble .
Hope that helps