It is. I think Red Guard is crap and the bottom of the totem pole in that category. If your going the liquid route then Hydro Ban is tops. Then Aqua Defence. I would not use any other brand. I quite using liquids myself about two years ago and switched out to Ardex 8+9 for my non steam shower builds. Your meeting is not going to go very well. I think you best contact the city hall and see if they have any local requirements. You are surely going to piss off the workers to no end highlighting their lack of skill set. I help design showers all over North America and on most of the projects I help over see my involvement goes over like a ton of bricks. This is likely going to play out the same way. You will hear things like "This is how we always do it" "It's fine this way". But the instructions for even just the backer board have been skipped. This by itself is one bad thing. Had even some poly or a double layer of building paper been used you would at lest have a shower that was done right at the lowest level of shower building.

Guest bathroom shower surround, glossy white tiles, "regular" TEC grout, 2008 I think. MB and hall bathroom tub surrounds, glossy white tiles, TEC XT grout, 2011. No issues. The XT grout doesn't require sealing, but can be, using a solvent based sealer. We have moderately hard water. We wipe down the tub surrounds with a microfiber cloth after showering (to prevent water spots on the glossy tile). I clean the bathrooms pretty much weekly. I spray the tub surrounds with 7th Generation disinfecting bathroom cleaner spray. Let sit a few minutes, and wipe dry with a microfiber cloth. Tile and grout look as they did when first installed.

Tough for anyone to offer much of anything then. Also it should be on them to clean somehow as anything you may do to the floors will end up on you as in he washes his hands as you worked on the floor. And whoever touches it last......................

If you have a curb, you will have the cracks develop there, too. and where the walls meet the floor. Anywhere where two different materials meet or where one surface meets another that is in a different direction (known as "change of plane"). My contractor still grouts such places, too. But I did a solid surface shower that he could not do wrong. I am keeping an eye on the place where the floor meets the shower pan, all other places are in dry areas. So there it is just cosmetic. I would guess that water can get behind your tile with those cracks. If properly waterproofed it is fine, but if not, I would get to this as soon as you can. A lot of shower builders do not use waterproofing, even though it is now required. If you do a search on this forum for "Shower waterproof," you can see many discussions about it and learn what is and is not waterproof. (Redguard yes, Durock no, for instance.)