No, They are not but they are not fixed neither you can move them to accommodate a custom height.
i need to purchase more shelves for this cabinet, where can i order these
Yes you can cut the bottom
It's 24" deep and 18" wide
I would guess Walnut. The company may actually know exactly.
All sides have oak finishes just the back is raw which usually go against a wall to anchor it
No you just remove hinges from style frame and rotate door and attach to opposite side of face frame. Very easy to do.
No room for crown molding. The door comes very nearly to the top of the cabinet.
Yes. however you can adjust the shelves