In What Ways Does Damage Get Calculated?

WARNING: SOME MATH!

I've been wondering about certain damage calculations ever since gavel came out and therefor decided to make this thread.

There are several ways to deal extra damage that isn't weapon damage, those are:
+X% melee dmg
+X melee dmg
+X% spell dmg
+X spell dmg
+X% strength bonus
+X% double damage chance (dexterity)
This is excluding stuff such as poison, thorns, reflection and idk what, if any other thing effects the damage ON THE INITIAL HIT and spell damage, please tell me.

For my following examples I'll be using a wand with 50-50 neutral damage and each attack takes 1 second to be able to re-use it; Because it's easier to calculate it that way.
I'll also be filling each X in with 50.

If I were to use this wand with it's melee attack once and dexterity activates will I be getting:
A: 50 (from the base dmg) + 25 (from the 50% melee dmg) + 25 (from the strength bonus) +50 (from dexterity) + 50 (from the raw melee dmg)

which would equal: 200 neutral dmg per hit (also equaling 200 neutral dmg p/s)

B: [[50 (from the base dmg) + 50 (from the raw melee dmg)] x 3/2 (from the strength bonus)] x 3/2 (from the +50% melee dmg )+ 50 (from dexterity)

Which would equal: 275 neutral dmg per hit (also equaling 275 neutral dmg p/s)

Or perhaps any other variation of this. (If any of you know, please tell me.)
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A question which would be answered if the question above would be answered but I still wanna know apart from eachother: do melee dmg% and raw melee dmgs stack or add?

Because if it stacks, that could make for some rather overpowered material and if it adds well...
Let's just say that you could theoretically use the cancer helmet with high +tier attack speed
and a Taurus chestplate with little -tier attack speed to get a super fast weapon that deals over 2k damage on average. (skill point extra damages included.)

I'm wondering this same thing with spell dmg. (even though we wouldn't get the amazing over 2k dmg super fast attack speeds with that. ;p)
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Now that I've talked about melee damage, let's start with spell dmg.

I've once read from someone that spell dmg is now based off your dps.
Therefor I'm assuming that (in this case) the mages meteor does 5x your dps.
My questions are:
1. When calculating your dps, does it actually calculate what your dps would be or does it calculate your first second. (the second case would mean that people with super slow attack speed would still get the same amount of damage in spells as people with very slow attack speed. if all the other stats were the same.
2. How does the mages heal get calculated?
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tl;dr
If you don't wanna read it just move on, I can't think of a good way to ask this short.