I have used limestone in baths for many projects and I have limestone in my own master bath (counter, floor tile, and shower floor tile). The counter is holding up fine, though I never let anything stain it. The floor tile is also holding up fine; we do not use any strong cleaners. The shower floor tile has faded a bit in color, and we are careful to rinse off any cleaners right away.
Bottom line: limestone is beautiful but fussy.
Q