Yes, you can.
Old floorboards tend to cap and move; being individual boards. Putting down a backer board gives you stronger/flatter stable floor.
fins to wall
It is best to remove the wall tiles. You need a flat service and a lot of times old tile will not be perfectly flat. If you remove the tiles you will have a good base to tile on. If you don't want to remove the tiles you may be able to add a backer board on top of the old tile and then tile on that.
If one doesn't want to install plastic wall panels there are a few alternatives to this. The first is that the individual can use gypsum board or cement board. Each of these are a great alternative to plastic wall panels.
No
Cement board is installed in the same manner as dry wall. It is an alternative to green board and is a lot better in locations that have wet conditions like shower stalls.
Gypsum is used for wall board.
The difficulty of installation depends upon the type of shelving. It could be as simple as securing a board to a wall.
Improper tile grouting will allow water to ingress to the surface of whatever the tile is laid on to ie plaster wall , concrete backer board , this will in time lead to the tiles becoming loose and damaging decoration in adjoining rooms
You can do anything you want, this is America! but seriously, directly to drywall is a bad idea. Drywall will wick the moisture, and you will not get a good bond, and, could mold and mildew. use a 1/4" Backer board, like hardiboard, and screw that to the existing sheetrock and into the studs. Then, you can either use a thinset mortar on the backer board, and the cultured stone pieces, or construction adhesive. If you use like, liquid nails, you will want to get collored grout or caulking, prefereably grout, and fill in your joints. Stagger any cuts so that they do not all occur in the same area. Piece of cake.
Read your governing documents to determine the extent to which you can modify your windows.If you want to install a different kind of window unit in an existing window 'hole in the wall', board approval may be required.If your question has to do with an air conditioning unit, again, you may need board approval to install such a unit.
The correct way is to install a 2x 6 backer plate between the studs where the cabinets are to be hung. If there is not one there you can tear out the drywall and install one. However the base cabinets can be attached using metal drywall screws or lag bolts. Since the countertop will put weight on these they really wont go anywhere, the wall cabinets are the main concern. you can try to use metal stud screws and lag bolts on them as well.