On the refinements, doesn't the character have to "column" the skills in thaumaturgy, making a +4 crafting frequency impossible?
You'd be better off stating that the character used that refinement for focus items, and has a magic bullet loader that grants him +4 frequency.
We have a character VERY similar to this in my game, only he skipped the "magic gun" type stunts in favor of just running as a very specialized thaumaturge (in crafting). I think he's at +1 frequency, +1 strength in specialization, with a focus item granting +4 strength (2 refinement), and has 9 potions at x2 a day... which he keeps loaded in a variety of old-school double barrel guns. Technically, he doesn't need the guns, but he likes em.