First be okay with the fact the bathroom tiles might need to be replaced. All of them. Replacing them in the bathroom will have the least impact on the rest of the house and whatever comes out in one piece, can be stored for future cracks. Maybe you can find a similar color but a different size, so it won't look too awkward, just an idea. Taking out a cracked tile is quite easy. Put on some gloves and safety glasses and (carefully) smash the broken tile with a hammer. An old screwdriver or chisel will help you tilt the pieces out. Work from the hole outwards to remove the other tiles. Removing a good tile is nearly impossible. Assuming it is still glued firmly, I'd say impossible. But, if you want to try anyway, you'll need to mill out the grout and then figure out a way to lift the tile..

I would not recommend glossy tiles in a bathroom. We have 24" polished porcelain throughout our house, and... we also have a pool. Although I love our tiles, I have to be super careful coming inside. If I am at all damp, walking on the tiles is tricky. Yes, they are easy to keep clean, but so are most tiles. For my master bath, I went with tiles that had a high COF (Coefficient of Friction). I've had my fill of slippery bathroom floors, and wanted something that I didn't have to slide a towel around on. I love them! I can step out of the shower, and have as much grip on the floor, as if I had stepped onto a mat. :)

I'm finding it a little hard to see the detail. Can you enlarge the top 2 plans?

Total reno of bathroom and ensuite. Need to keep in cream tones not grey as bathroom door needs to stay cream as per all other doors in house and interior colours. Sampled grey tone tiles and they clashed. New vanity below, light oak, pic of old ensuite, and ideas. Want to keep wall and floor at 600x600mm. Selling house so wide appeal needed. Darker floor and white walls ( by either dark tiles or a darker timber effect floor as pics) OR white floor and walls (do they need dark grout as per example below)? Will 600x600mm work for both floor and walls. Will 2x 600mm work up walls, dont want to go 3 high. Doing this to keep costs down. Painting everything else white and installing white shutters. Showers to remain as is, glass with aluminum frame.