I like the complicated aspect of this class, as well as how much creativity it affords the player, but I'm astounded that it doesn't utilize shapesand as a base mechanic.

Shapesand is an affordable item on it's own, the sandshaper is a good example of how to boost it's effect with class features and how to balance that.

Also, I'd like to see a builder Su power that turns any sundered object or part of, up to (5'x5'x5') into a brick version of itself that can be pocketed and placed anywhere else to it's original size and condition; minecraft la mode.