Leader Accessories A Pair of Elite Low/High Back Folding Fishing Boat Seat (2 Seats) (White/Grey/Blue)

Does the back of the seat have to be at an angle? Or can it go straight if I was putting it against a wall

Are the bottom cushions removable for installation? I would like to screw the seats to a project without using a mount.

Do the seats fold flat so I can flush mount them in my casting deck?

What does "low/high back" in the "d" item title mean? what do the letters before the colors mean?