That sounds like a maintenance item that would be the homeowner's responsibility. Insurance covers damage, not normal wear and tear or deterioration.
The costs will vary according to the quality of the corner shower stall. However a medium quality corner shower stall would be about $6000 to buy and install.
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.
A typical shower door is 72".
You can put it at any height. Unless there is some other reason not to, something structural, I always put them above the shower stall for taller people.
WXYZ is a trapezoid......
it has a toilet, sink, shower and tub. (if it has a shower stall and no tub it is called a 3 piece)
There are many products you'll find to clean your shower stall at the grocery store. Once you have it all removed, a great mold preventative is to spray some vinegar water in your shower stall after each use. Also be sure to use your bathroom fan, and to keep it running long after you've finished bathing.
intake gasket is leaking
Yes.Have insralled many in yachts.
it will poo
24".
Shower is water that is sprayed over someone. Plumbing is the fixtures and piping that supplies water in a building. Shower plumbing would be the fixtures that spray water in a bathtub/shower stall.