It can either look really dramatic or too dark, depending on the size of the room as well as your other components. I've attached a couple of images of our work using dark tiles, the smaller bathroom we have surrounded the bath with dark tiles but then balance it with an extra large mirror to bounce the light around the room. The larger bathroom we have taken the floor colour way onto the wall but used a different texture on the walls for drama. Hopefully this gives you more of an idea but you shouldn't to nervous of the room being dark, it's where you can create a contrast as well as textures. Look forward to seeing what you go with in the end.

depending on the size of the existing vanity it should be possible to have a similar new vanity or a custom unit made to replace the original but a chat with a plumber should be arranged to recommend suitable options and plan a schedule to remove the old and install the new, including any necessary waterproofing or tile repairs..btw careful removal could allow the original sink, taps and even the counter to be saved and recycled into a new vanity that matches the bathroom perfectly with the added option of being able to add different doors or drawers to the cabinet

Yes thank you for your thoughts. the room is 2.8 (with window) vs 3.4m. I do find it a bit annoying too as I don't like that you open the door and see straight away into the shower (though I'm certain the door would have a lock). I'm sure they lined the bath up to be with the window as visually that looks better, but then I find the space at the end annoying. I like the alternative drawings (I like three of them lots!) and I had been considering an drop in bath built wall to wall rather than a freestanding but also finding it frustrating to find a really nice supportive bath and there are less drop in baths than freestanding around at the moment which is a bit annoying. Thanks Anna for the picture, that helps as that looks good (though we would have more space at either end, 50cm) and I prefer the look of yours with some space but not as cavenous... I think I might have to have a talk with my husband as we really need to work out what to do!!

Amazing, can't believe it is the same space!! looks much more roomier. Well done!