Calculating Damage and Speed

Hi,

I wanted to know how exactly to calculate damage and speed. Let's start with speed. Let's say I'm using Haste and some passive nodes. Haste increases 15% and the nodes 33%. My weapon aps is 1.83.

Do I calc:
1. 1.83 (my aps) times 1.15 (Haste) times 1.33 (Passives).
or
2. 1.83 times 1.15 + 1.83 times 1.33

As far as damage goes, Does a gem like Added Fire Damage scale with phys nodes?
Does it scale with other gems like Melee Phys?
So let's say my phys dps is 300. My phys nodes increase in 50%. My Melee Phys gem in 25%. Added fire damage is increases in 15%.
Does the calc look like this:
(300 times 1.5 times 1.25) times 1.15 = total dmg?

Thanks.

the basic rule is:

all "increased" modifiers from all sources are additive (=summed up into one multiplier)
all more/less modifiers are multipliers

speed = base * (1 + increased_from_haste + Icreased_from_tree + increased_from_whatever_source.. ) * more_etc_from_multistrike.. etc

About the rest of your questions, added fire, hatred and other percentage adds are converted damage, they are converted from physical and all physical damage bonuses apply to them.

It's easiest to calculate adds and conversions at base damage level. If you have some base physical damage of 100, an also 15% added as fire, 20% added as cold and 40% converted to cold you will end up with:
60 physical
15 fire
20 + 40 = 60 cold

Then you apply physical increases and multipliers to all those and also elemental increases and multipliers to elemental parts, using that general formula from the post above. If you had some elemental damage that wasn't converted, you would apply only elemental bonuses to it, of course. That's one of the points of converting damage, you broaden the range of bonuses that affect those damage segments.