Great overview. I think the D6 things is needlessly confusing, as simply writing 6D6 instead of D6 would be better.

The pool substituting Usage Dice sounds a little clunky, too. Why not use different dice? I get wanting to simplify the system with d6s only, but I think it backfires in some aspects.

The d6 pool for checks is really cool, though. The Procedures mechanics as well, I like that!