new damage calculation with set bonuses

So with the revamp of sets in 2.2 my question is how the new damage buffs get applied. are they all multiplicative from diffrent sets/legendary vs additive (stacking elemental dmg)

With the new Talrasha for example you have your Meteors procing all over the place, so by how much amp do they get affected?

With the Boots you get 100% extra meteor dmg and 200ish% if you hit less than 3 targets.

Tal 6 piece gives you up to 600% dmg buff.

Ontop of that you want ideally to have meteor%+ skill dmg on your gear(tal OH always rolls 20-25%)

You can go even further and add 125% off the set rings(forgot name here)

Adding in the Rng of the Elemental Ring ontop of all the buffs, you see huge numbers sometime.

I have been going on Trial/error with my build/skills. and i like having the 4piece magnus for the dott bubble aswell for the stun cc.

This is my current setup, for anyone thats curious. http://www.diabloprogress.com/hero/footmunch-2387/Footmunch/58323323