Need help from a MinMaxer

I am trying to figure out how to max dmg on my Marksman and Engi and am wondering about some of the affixes which seem to be more prominent on the TC Patch.

There are alot of “increase damage by %” and “add damage %” on the mythic and double edged items now. Is there a difference like maybe the former being multiplicative and the latter being additive.
Also if remember right “increase damage” on armor was said to increas all dmg even grenades, strikes or even bots, is that right?

Also the Wiki lists nearly every affix as possible with any of the four feed types. There seem to be +Crit affixes with strength, stam, will or acc feed costs. I was under the assumption that crit allways costs accuracy?

I believe both are additive at least on items, even when combined. “Increases” typically refers to overall damage, and “adds” usually refers to elemental damage.
Elemental damage (I’m including physical as an “element” here) increases are worded as “adds” because it can add damage of that element if it doesn’t already exist on the item. Wording it as “increases” would imply that it has no effect on items that don’t already have damage of that element.

I don’t know if/how damage affixes apply to skill effects, or whether skill damage is additive or multiplicative when applied to weapon damage or otherwise total accumulated damage over all equipment, or if damage increases have different effects when applied to weapons vs armor.

Mod affixes can have any stat requirement because it provides flexibility and better optimization when spending attribute points. This was a change introduced in TCv4/MP 2.0.

When it comes to crit-related affixes that appear on equipment, they seem to increase all feed costs on the item by some amount. Sometimes it’s not enough to actually change them (values are rounded down from what I’ve observed), so an item could be augmented with a crit affix and the feeds could stay the same.

Thx, i am trying to figure out if it is viable to go crit as non sniper MM now that there exist a ton of other dmg affixes and stats seem to be more limited as it seems. Thought if i go the crit route i am goigt to spend tons in acc and when i go “increase dmg” or “ele dmg” everywhere i need willpower primarily but it seems i am wrong on both.

And my second char is going to be a droneless engi on which i want to squeeze out the last bit of bot damage now that strikes are less of an option. Therefore i thought increase dmg on armor might be beneficial in addition to Minion dmg.