Questions About Crafting

So I was thinking if this should go in the new crafting section or not but I mean it's a question so I just but it here xd
ok so yea questions
1. How exactly does durability work?
I still don't rly understand although tbf I didn't rly look around at all either but if someone could explain that'd be nice xd
what I don't understand as in how does it go down? Per hit received? Per spell cast? Per melee hit? Mobs killed? Damage dealt? Time worn? etc

2. Does double negative work?
As in using Obelisk Core to flip around some id's and some gimmicky crap like that. It doesn't work with elemental defenses tho so I'm assuming it doesn't but just wondering cuz otherwise there don't seem to be many useful applications for it...

3. Ingredient Id ranges
Are these determined before or after using them? For example, do you know exactly how what Id's an ingredient will give when you use it or do you only find out after they're on the weapon?

4. What about ingredients with set Id's?
I'm assuming these aren't dropped normally but just wondering. Are there merchants that sell them or are they exclusively quest rewards? Are there ways to get multiples of them?

5. When an ingredient says to *direction* of it, does it mean the one that's immediately next to it or everything in that direction of it? Cuz I'm looking at this ingredient and wondering why it can't just be -100% ingredient effectiveness to ingredients touching this one


So yea thats about all the questions i have ty in advance for answers uwu