Concrete backer board is usually used as an under layment for ceramic tile. It can be used on walls, floors or countertops. It has a solid core and is faced on both sides with fiberglass. It's an ideal under layment for wet areas like shower walls and bathtub surrounds, and is typically mold resitant.
The material that is used before tiling a tub surround and ensure no water damage is known as concrete backer board, sometimes referred to as green board.
Yes on wood, no on smooth solid concrete
a concrete or masonry blade
Pull it off with pliers if that's easy. If not, cut out the backer board and renew it. It should be done when new tiles are done anyway. Use a fibre or concrete backer board, NOT wallboard.
Ceramic tile can be installed over any non-compressible solid, non-flexible surface, but in areas of high moisture or possible water penetration, a cementious or water impermeable backer should be used to prevent rot.
Plywood is the best choice between these two. Particle board can swell if water gets to it. You would be better off if you use a tile backer board. Concrete based or a fiber type. They are made for this application.
Old floorboards tend to cap and move; being individual boards. Putting down a backer board gives you stronger/flatter stable floor.
Generally the tub is nailed to the studs and the backer board or sheetrock is put over the tub or just down to the top edge.
Replace the drywall with tile backer.
Yes, you can.
No you not have to put backer board behind the tub below the shower stall area. You only need to use it behind the walls of the shower stall.
If you are talking about a fiber cement backer board, the manufacturer of the board should provide the answer you are after. I am currently using Hardiplank to reside my house, and the manufacturer recommends attacheing the TyVek house wrap to the wood sheathing per TyVeks recommended process. Hope this helps.