Bow and Bow attacks

Im trying to make a Bow centric build and i was very unsure of how a specific stat in the passives tree worked. "Bow Damage" 12% increased physical damage with bows. How does this apply to things like Split Arrow and Lightning Arrow, specifically does the physical damage increase from the passive get added in before the S.Arrow and L.Arrow damage is calculated? Does it only effect part of the attacks or the whole thing?

How does added elemental damage on weapons factor into the dps S.Arrow and L.Arrow dps? Do the added elemental damages get added in to the dps or are they ignored, the wording on L.Arrow says dmg is 50% phys converted to lightning so does this mean that added elemental damages are left out or are they applied after the phys->lightning calculation?

This is for a standard league non hardcore build, just something for me to have fun with. Right now the passive tree is changing constantly, mostly because im not sure how these 2 things work and partially cause im indecisive.

You probably should check out that topic with mechanic basics and read up on damage conversion in detail, but I can probably clear up the basics at least.

- It's probably best to start with your base damage, if you're a weapon user that's the one you see on your bow on the top, and if you're a caster that's what you see when you hover over your skill gem. In case of weapon users you also add damage on jewelry and other items to the base damage of your character.

- So, you might have 100 physical damage, 50 cold, 30 fire and 20 lighting as your base damage from your weapon and other gear and let's say you also use hatred aura and added fire on your lightning arrow skill. Adds and converts are based on your physical damage, so the base elemental damages of your lightning arrow skill will look like this (if we forget about that 0,7 damage effectiveness multiplier):
50 physical
50 converted lightning (50% physical converted to lightning by LA)
30 converted cold (30% physical added as cold by hatred)
40 converted fire (40% physical added as fire by added fire gem)
20 lightning
50 cold
30 fire

- Now, the 'converted' elemental damages are kept separate because they are based on physical damage so they are affected by physical damage increases and multipliers, while straight elemental damage is affected only by elemental bonuses. 'Projectile damage' bonuses affect all damage you do with any projectile, it might be physical, elemental or chaos, or it can be attack or a projectile spell.

This is immensely helpful, Thank you!