The walls do not show any sign of waterproofing whatsoever.
If you install the shower screen next to the tile, then rely on Silicon to hold in the water, that's bad practice, unless you don't plan on using the shower, in that case it will last forever. That area will get loads of water/moisture from showering, the Silicon will eventually fail, and the water will find a way behind the shower screen causing water damage.
A shower should be functionable before anything else.
I like those wavy tiles
Yeah course you can so long as it doesnt move or leak , is your own house .
Ideally needed a shower channel that worked with the tile and tiled to edge of tray
To me looks like a channel might go wave to wave hard to say
Id wing it by , fit the screen channel 3-4mm away from tile edge .then scrape out depth from the 3-4mm gap and seal with something good ?
Check the instructions for shower screen some need be sealed on outside only , then would be a problem