As far as damaging the K3 using the case, just be cautious and careful. They case for the KDXG is nice, but if you open the case from the backside and put too much pressure on the hinge clips you might damage the Kindle. However, you have no reason to open the case from the backside. Always open the case from the frontside. If you are concerned that you might accidently open the case from the backside then use a small amount of velcro to stick the back of the Kindle to the inside of the back cover.

Of course this is a brand new Kindle design coming out. So maybe they also redesigned the hinge clips to prevent accidents. It would be pretty simple for them to improve it.