You could consider ripping out the shower base and tiling the existing 830 wide and extend that all the way to the existing bathroom wall at the opposite end of the bathroom wall. It would create one wall at an angle but with a seamless glass shower screen and a new tiled floor and walls it wouldn't look out of place. That would allow far better body manoeuvring in the shower.

Hi. If you have an existing drain via your shower, this can be converted to take care of a bath shower combination, even if you also need it to be a wet floor drain. A bath waste is normally a 40mm pipe, so if your existing pipe is a 32, you might need to do some conversion

Couple of observations Lots of mosaic tiles have sharp edges so you need to be very detailed in how you do this. Have you considered a corner (spayed front) shower bath combo. There are several manufacturers that make these in fibreglass and acrylic materials (some with spa jets also). That way you can consider a shower screen that would be integral.

Hi RE your relocation options, the plumbing is probably going to dictate what your design options really are. Apartment renovations are quite a bit different to normal reno works in that there are often a lot more restrictions as to what you can do. For example, in older buildings, the drain for the bath is often a smaller diameter pipe than the shower as it doesn't need the flow rate. This means that moving the shower to the bath results in long high pressure showers filling up the floor (so you definitely need a hob) because of poor drainage, particularly if you don't keep hair out of the drain. As the floor drain plumbing is often situated either within the slab or penetrates into the ceiling space below, it is not able to be changed without major works and cooperation of others. The water supply and the waste usually go back to a plumbing stack so your options also depend on the proximity to that. Many things can however be done, but the overall plan of the apartment needs to be looked at re stack/access to pipes/check pipe diameters. With a bit of creative re-working we have installed additional toilets and shown other residents some of the possibilities in the apartments we have done but every apartment is different. My tip would be to do some research within your complex as to what has been done by other owners and speak to them about the issues they had to overcome. If you don't know of any you could easily do a web search for your street address and you will see previous advertisements for apartments for sale along with (usually) pics. You could then approach them and ask how it went. It mightt save you some $$$ and time. Cheers