Maker - Alchemy Skill FAQ and Walkthrough

FIRST

So to make a White Fangz, I'd need 4 Mithrils, 28 Mid B crystals, and then if I wanted I could put a diamond and str crystal (Because it says it has 2 jewel slots).

Correct.

Your #2 came out a bit garbled though because you're mixing terms.
I believe you're referring to grading jewels & crystals? Monster Crystals themselves are forged into levels based on the levels of mob etcs supplied, with a slight chance of getting better ones. I don't think anyone's got an exact ratio for how frequently a monster crystal comes out exceptional, or how often crystals and jewels grade at each level.