You could tile right onto the stucco, or this will work if you can keep it out of the weather.
Yes, a masonry blade will do just that. BUT, it will create an incredible amount of dust! You must wear a dusk mask and goggles, and cut outside. It is not recommended to cut Hardie board that way, but rather with the Marshalltown scoring knife that has tungsten carbide tips. I can understand your frustration with this slower cutting method, but once you try cutting Hardie board with a masonry blade and see the volume of dust it creates, you might have second thoughts.
I would not recommend using this without some other structure to support it. This is designed to lay on a subfloor and doesn't have enough strength to support standing on. You could probably use it on wall framing but not on the floor by itself. I am able to bend and break the 1/4 board with my hands.
Normally they use what is called a rodent barrier. And then 6 mill visclean on the ground
Absolutely. Just make sure you anchor into the studs. I do this same thing regularly. Good luck and have fun, Jim G
If im understandingthe question correctly you are talking about the inside of the cabinet. the backer is not water proof. Replace it and caulk with silicone
Yes of course.
Yes You can use it but Use 1/2 inch
Yes! However it may void any warranty. I have done this several times.