As I have written elsewhere, we're seeing a rash of poor counter installations lately. You are getting good advice here. I don't understand why your counter person installed a faucet. Sure, they drill the hole(s), but normally the faucet is installed by a plumber. Also, I do not understand why any glue was in the vicinity of a faucet installation. As for the attorney threat, I wouldn't over worry it. I don't know where you are, but in most places he's have to give an attorney a couple of thousand $$ to even listen to him on a contract matter. Of course, if he has one on retainer (not likely) he probably has to sue a lot, or gets sued a lot!

Big edit for this post, you posted the Kerdi shot while I was typing. So... 1) The flex in the floor that is causing the grout to crack: It's possible that the Kerdi Tray was not properly bedded in thinset, so as the slightly flexible tray flexes, the inflexible grout is cracking. It's also possible that the small size of the penny rounds is resulting in point loading on the foam tray. The foam compresses ever-so-slightly, the tile moves, the grout cracks. The floor...Is your guy using thinset as grout? Grout as thinset? With the penny rounds, it almost looks like he's doing an all-at-once installation. Setting the tile, promoting between-the-tile-squeeze-through, then grouting. All at the same time. A negative with that is that he's grouting and cleaning the grout before the thinset has fully cured. When I grout I'm pretty aggressive with the grout float in order to get grout into every nook and cranny. I don't want to leave any voids. If your guy took it easy when grouting so as to not displace the unbonded sheets of penny rounds, he could have left a few voids beneath the surface. If he wanted to be gentle while cleaning the grout, he might have used too much water during cleanup, that can also weaken the grout. I don't know why the floor is being grouted piecemeal. That's an easy way to get uneven grout color on a floor. As he continues to tile, he'll have to chip out parts of the hardened thinset/grout at the edges fo the already installed sheets to get the subsequent sheets of tile to mesh with the already installed sheets. He'll need to be careful to not ding the Kerdi membrane. It's also a recipe for mismatched spacing at the edges resulting in being able to see the individual sheets of tile versus the floor being one harmonious surface of penny rounds. With him sliding the floor tile under the bottom course of wall tile, I do hope he's not leaving any unfilled voids in the floor-wall corners. 2) Bullnosing. He bullnosed the tile after they were on the wall? Yeah. Probably not going to get a good outcome. Should be an easy remove and replace. The bowed wall? The tiler tiles on what he gets. If he gets a bowed wall courtesy of the framers, he can put the blinders on and tile right over it...or he can address the bowed walls with whoever hired him...the GC? The homeowner? Then the tiler can either tile right over the bowed wall, OR he can have the contractor fix the wall before he tiles, OR he can repair the wall himself and then tile. One added item...I can't tell what exactly is going on int he bottom left corner of the already installed tile. Could simply be that the tile spacing is skewed and he lost the pattern. After this floor is done and everything cured, I'd recommend having the GC pull the drain grate, install a plug, and flood the floor. As the floor tile is covered with water, watch for air bubbles. They'll indicate voids under the tile or in the corners. Once flooded, pull the plug to see how the floor drains. Make sure it drains completely and that water is not held in the corners. With a Kerdi Tray, the slope of the floor and a properly draining floor should be a no-brainer. But based on what I'm seeing and what you described regarding the bullnose, this could be a "no brain" installation. Sorry for that. Remediation after-the-fact is always a tough spot to be in. Good luck.

The pictured wood-shim-and-polyester-over-the-flange method of supporting a sink is a guaranteed failure without additional support. I'm not crazy about the shelf brackets. I'd be a toughie, but you could still get a Hercules Universal Sink Harness (Braxton Bragg) or a Sink Strap (Regent Stone Products) to support the sink. If you did, you could stand in the sink without repairing/replacing the cabinet. The front rail on frameless cabinets is nearly only decorative in nature; it functions as a doorstop and as a stretcher to keep the cabinet sides apart when the HUSH or Sink Strap try to pull them together. I wouldn't worry about it. When you strap the sink in place, you've turned the sink into a 9" deep stainless steel truss which supports the stone better than any melamine. I'd make sure they applied a generous bead of silicone between the sink flange and the granite bottom. See if you can slip a thin knife between them, please. A topical bead is useless. If they can't/won't do a strap, angled aluminum can be fastened below the cut melamine to support the stone:

are we going to see any problems in these dry areas from the way these tiles were set? While the cavity is open, try tugging on the end of tile with your fingertips and see if it just pops off. If you want to get crazy, wedge a flat bladed screwdriver in there and test just how much force it will take. My bet is that the tile will break before the bond fails. Keep in mind that thin-set goes on the wall with a notched trowel in the first place. The voids are by design so the tile can be nestled into place to compensate for substrate irregularities. I would not be worried about this installation at all if the tile stays put with the tug test.