Maker and Black/Dark Crystals

So black crystals can't be use to increase stats but all the rest? (IE: Attack, Defense, Accuracy, etc)
Is it a good idea to use Black and Dark crystals to make your items?

Not really. Usually you'll only be able to afford an intermediate and you'll end up with like +1 to all stats. You're better off using stat crystals. People really only use them when they're trying to make equipment as best as possible.

Question 1: Are dark crystals applied before or after stat crystals? If I used a dark crystal which gave -3 and a str crystal which gave +5 on an equip with 1 stat normally, would it end up with 5 stats (1-3, changed to 0, +5) or 3 stats (1+5-3)?

Question 2: what's the probability of chaos/dark crystals lowering or raising stats? I know chaos scrolls take 5 "trials" where they raise by 1, do nothing, or lower by 1, something like this:

 too bad I suck to much to actually write a program for this or know how to do it with distribution and stuff

Trial	-5	-4	-3	-2	-1	0	+1	+2	+3	+4	+5
1	0	0	0	0	.0.333333333	0.333333333	0.333333333	0	0	0	0
2	0	0	0	0.111111111	0.222222222	0.333333333	0.222222222	0.111111111	0	0	0
3	0	0	0.037037037	0.111111111	0.222222222	0.259259259	0.222222222	0.111111111	0.037037037	0	0
4	0	0.012345679	0.049382716	0.12345679	0.197530864	0.234567901	0.197530864	0.12345679	0.049382716	0.012345679	0
5	0.004115226	0.028806584	0.061728395	0.12345679	0.185185185	0.209876543	0.185185185	0.12345679	0.061728395	0.028806584	0.004115226

Oh, if you're trying to calculate a lower-level crystal, just look at that row. For Intermediate dark (-3 to +3), look at the third row. And that's probability, not percents, so .185= 18.5% chance of that happening.

Edit: Nevermind, done. Still want to find Noah's post to double-check.
Edit 2: Found a made a minor mistake, fixed it.