Help with Spell damage formula/equation in 2.0+

Feel free to answer any question you can if you can't answer everything!

I read in the 2.0 post that the damage formula changed in various locations, namely with spell damage conversion, however the conversion aspect makes sense to me.

1. What I don't understand is how exactly the new "additive damage" pieces in.
As described on the 2.0 post: "There is now a third damage bonus type, only found in Ability Trees called Additive Damage. It is added as pure damage not affected by your spell attack speed modifier before item bonuses kick in. Contrary to Raw, it is not modified by your spell damage multiplier. This means that fast attack abilities are more affected by it."

Spoiler: Link to 2.0 changelog

https://forums.wynncraft.com/threads/2-0-spellbound-changelog.299715/

Does ALL damage additions listed in the ability tree count as additive damage (excluding the spell conversions of course)? For something like "Earth Mastery" which says it adds +2-4 earth damage, then +20%, these numbers show up in the player stat breakdown (I believe) which would lump them other "Raw Earth damage" identifications(like from tomes); does this make it not an "additive damage"?

2. How does "Raw Elemental damage" apply to multiple elements? If I have the Epilogue boots which add 235 elemental damage and a Rainbow weapon, does every element do +235 elemental damage? Or does each element do (235/5 = 47) more damage? From the few tests I've done it seems like it's the latter as my average hit without them was ~400 less. It wasn't a very sanitized test, but by only taking off the boots and changing nothing else that's what I got, both for spells and main attacking.

3. Does Raw damage (not typed to main/spell) apply to spells? I want to say yes since there is specifically Raw Main damage and Raw Spell damage differences, but I'm probably getting myself confused thinking about all this.

3.1. If Q3 = Yes, then what multipliers does the raw damage get affected by? +Dmg%, +Spell dmg%, +Elemental dmg%(if it is the same element), Attack speed multiplier?

4. Non spell-related: Is Explosion damage (from exploding ID) just 100% of your base dmg in an AoE, or is it affected by the various main attack multipliers like +dmg%.

4.1. Are player/monster explosions all neutral or do they inherit your elemental spread like spells do since 2.0?

5. For elemental weaknesses, I've heard it described as true damage, not affected by your defense stat. I found this video from pre-2.0, and AFAIK it probably works the same way:

Spoiler: Video

https://forums.wynncraft.com/threads/elemental-defenses-explained.293835/

What I didn't get from the video was if ID modifiers like +damage% affect the damage you deal to enemies in their weakness. ex: +50% dmg IDs, enemy has -100 water def, I hit for 50 base water damage and a normal, do I do (50*1.5)+100=175 water damage, or (50+100)*1.5 = 225 water damage?

6. For spells, are +dmg%, +spell dmg%, and +elemental dmg% (on respective element) still added together and the multiplied with the base damage? The PDF linked below seems to indicate that, but it doesn't feel correct from my firsthand experience.

6.1 Not always spells, but I've seen my friend turn about 8000 main attack damage (Stinger, a bunch of +main attack damage items) into a hit that does over 200k damage, that would be a combined damage % increase of 2500%, so his various damage % increases must be multiplying together as getting a 2500% increase from adding %s seems like way too much. At the very least Earth Powder's Quake has got to be a separate 4x damage multiplier, which would lower the % increase requirement on such a hit to 625%, which still seems very high for additive % multipliers IMO.

I have tried looking around for info, but most of the information is from pre-2.0. Wynnbuilder links (and probably uses) this document: https://wynnbuilder.github.io/wynnfo/pdfs/Damage_calculation.pdf which is from 1.20.1 (3 days before 1.20.2). There is definitely useful info in there, but it's not very easy to follow for me despite their best efforts. Having "The final formula" being "TBD :(" makes me very :(.
I took a peek into their Github repo as well to see if there was a file with a simple name like "damage calculation", but after 10 minutes of snooping around I didn't find anything clear cut.

Me and my friends also tried looking for Q/As in the official discord and the developer discord, though the latter was more for API questions.