I too am sorry for what you've been going through. If you look up my name, you can read about our saga with our builder. Not quite as bad as yours, but not good either. Our 12 month build turned into 27 months, because our living room floor being unlevel by more than 3" from one end to the other, windows being put in wrong, and lots more, we lost a special tax savings that would have shaved close to 2k a year off our taxes.
We wound up taking our builder to court (Make sure you're using a CONSTRUCTION lawyer) and shaving a large chunk of money off of what we had to pay him.
The problem is as bad as it is here in FL regarding construction, i beleve TX is worse.
Adding to Beth's excellent comments about waterproofing and how tile is laid out, I thought I'd post my pony wall which was done with tile. Notice how I got special tile that finished off the edge?
My curb is granite.
My shower head is also perfectly centered on the wall to the right. Notice too how the floor tile is perfectly laid out. Like Beth, the tile guy made sure it worked before laying the first tile. And if you look carefully you can see based on the back wall tile how the floor is sloped towards the drain in the center.
And like Beth's floor, notice how my floor is perfectly level with no lippage? And also how the pattern was laid so you can't tell where one tile starts and another one ends?
BTW: Be sure to wish your "builders and lousy subs" Karma. When we moved in 5 years ago, we wished our builder Karma. He's getting his now. I can't say how, but he is. ;)
Q