I understand it uses the held berry but
1. Is the berry used up at all?
2. What are the types/power of the berries?
3. If a berry, such as oran or sitrus, is consumed will natural gift just fail?
Yes the Berry is used up
Here are the types and powers: http://bulbapedia.bulbagarden.net/wiki/Natural_Gift_(move)#Effect
Yes it will fail if the Berry has already been consumed
These questions have been answered before, look around better before asking