What at a fantastic find Rebecca. I also have a cork floor, and have found it faultless....even though it will be replaced. I'm not sure why it is so overlooked, as I'm doing the same despite knowing its benefits firsthand?? it needs to be featured across design, maybe it's just not marketed, designers are doing themselves a dis-service, but perhaps it needs a marketing shake up. I vote yes for cork. ML DESIGN

Be sure if you want to replace the tile to remove the grout between the tile to be removed and the surrounding tiles. Once this has been done then all you need to do is break the tile to be removed with a hammer. Remove all the glue on the wall then once cleaned, install the new tile.

Some ideas below including use of picture frames, stencilling, fabric cover, looking like a window.

Are your floors a concrete slab or timber ? My previous home had a similar problem, but was on a concrete slab, And we had wall damage in the hall. A company like Megasealed will come and fix this in a day. They will remove the existing tiles, re water proof, and relay tiles. And also regrout the entire shower recess. If the paint in the hall is not bubbling, then you may be correct that the damage is in the floor, not the walls. And since you have not used the shower recess for a time, then it is the ideal time to get a professional in to redo the shower base. With reference to removing the hob, this may be making the job an expensive full renovation. As the hob would be built up from the floor, the tiles would not be underneath, therefore you would be having to take up that hob to the concrete/timber base, then the domino reaction may take into effect. New floor tiles, new levelling of floor etc etc.