Doors are weird at the moment. You can duplicate them simply by placing a door and destroying it.
EDIT: Similar with chests. They keep reappearing in my inventory after placing them.
EDIT2: If chests are stacked on each other, you can only open the top chest in the stack. In vanilla, you can open the bottom chests too.
EDIT3: Seems like you don't get any flint by destroying gravel.
EDIT4: When getting shot by a skeleton, the death message says: "Player was killed by a ArrowEntity"
EDIT5: Trees don't drop saplings
I will create bug-reports soon.
EDIT: Similar with chests. They keep reappearing in my inventory after placing them.
EDIT2: If chests are stacked on each other, you can only open the top chest in the stack. In vanilla, you can open the bottom chests too.
EDIT3: Seems like you don't get any flint by destroying gravel.
EDIT4: When getting shot by a skeleton, the death message says: "Player was killed by a ArrowEntity"
EDIT5: Trees don't drop saplings
I will create bug-reports soon.