Difficult to fully understand the issue without seeing first hand. But looking at the picture can you not grind out some of the metal support to allow the pipe to sit closer to the tub. Would that give you a better angle?
Would have been nice to have pictures from further away but they do show the challenge you have. I think you have done a good job but more filler and paint I think is unfortunately going to be needed to achieve the finish you want
Perhaps no surprise but it isn’t clear to me why they would hide the true scale of the deaths. China I can understand. Is there something I have missed that would explain the coverup?
You could cut a section out along your garage and fill with gravel to allow water to soak away.
cheap grinder with a masonry cutting discs should be all you need
Looks like a fast drain version. I picked up one from B&Q a number of years ago for an old house.
is the intention to replace the full thing or are you looking for the same product just to replace the top cover?
https://www.diy.com/search?term=Shower+trap
It’s a difficult one to answer without knowing where the bath will sit and then in relation to the others furniture.
my initial thought is to tile the right hand wall using the slate effect in a central band floor to ceiling.
but as said it may not work as the bath won’t be a conventional...