Exactly how does a Storm of Blades work?

Question

What is (probably) clear about this spell

1. I cast a Storm of Blades. I provide a Greatsword as a material component, probably from the False Focus feat.
2. If my Caster Level is 6, I create three such swords. Of course, I can boost it in many ways, as usual.
3. Then I roll a ranged attack roll for each one -- apparently using my BAB, Dexterity, and any other stuff normally modifying my ranged attacks in general, possibly even archery feats like Deadly Aim.

Then every sword that hits "deals the same damage as a standard sword of the type expended", and this part is very unclear to me.

It looks like Divine Fighting Techniques and Sneak Attacks are applicable too because it is me who makes the attack rolls. Because this spell deals damage, it probably counts for "+1 damage per die" things like the Orc Bloodline Arcana.

What is this "standard" damage?

1. 2d6, because this is the printed damage of a Greatsword
2. 2d6+STR, because this is the standard damage of a thrown attack. This means that most arcane casters would deal less than 2d6 because of dumped STR.
3. 2d6+INT (or another relevant ability score), because magic, and because I propel it magically
4. 2d6+1.5*STR, because this is what a standard Greatsword attack deals in most situations
5. Something completely different

Will this damage also change if I provide a sword of a bigger size?

1. A Large Greatsword costs 100 gp and is within the limit of False Focus. At the same time, a Large Greatsword is not a standard one. Will it affect the damage dice?
2. Would I have to accept penalties for using an inappropriately sized weapon? What if I also enlarge myself? A Gargantuan Shortsword and its 3d8 points of damage look impressive.
3. Would Lead Blades work as intended (provided that this spell generally functions with thrown weapons) and make my Gargantuan Shortsword deal 4d8 points of damage?

Do I require proficiency with the said weapon?

It may sound a bit contrary to what the spell is likely intended to do, but it does not say that I don't need to be proficient.

Answer 1

What is this "standard" damage?

1. 2d6, because this is the printed damage of a Greatsword

This is the correct answer. The spell Storm of Blades doesn't say "standard damage" it says each sword "deals the same damage as a standard sword of the type expended". The "standard" refers to the base type of the sword, so even if you expend a Holy Flaming Greatsword +6 for the spell, it only ever deals the damage of the standard Greatsword, disregarding all enhancements of the expended material component sword. However, it also means you can expend a broken sword as material component to deal the damage of a standard (i.e. unbroken) sword; the broken condition reduces the price of an item to 75%, which is useful in combination with the False Focus feat.

The spell doesn't say that it counts as a thrown weapon attack or anything of the sort, so you do not get to add any damage to it from high STR (or INT). The spell tells you how the mechanics work (ranged attack roll, no modifiers) and what damage it deals, just like a Fireball explains its own mechanics.

Since the spell does use an attack roll (and has "one creature" as target) it does count as an attack and any abilities that are based on mere attacks would work, e.g. sneak attack (but not necessarily on the second/third/... sword hitting the enemy).

Abilities that modify spells affect this spell as normal, since it doesn't say otherwise, so for example the Orc bloodline arcana would add +1 to each damage die.

Will this damage also change if I provide a sword of a bigger size?

Yes, same answer: The spell says it "deals the same damage as a standard sword of the type expended". If you expend a colossal Greatsword, it deals damage as a standard colossal Greatsword. The "standard" refers to an unaltered sword (no enchantments, no special qualities, ...), but a small Greatsword is a different standard weapon than a medium Greatsword.

Would I have to accept penalties for using an inappropriately sized weapon? What if I also enlarge myself? Would Lead Blades work as intended? Do I require proficiency with the said weapon?

No, to all of those. You do not use that weapon, so (non-)proficiency does not matter, and neither does your size matter.

The Lead Blades spell says it "increases the momentum and density of your melee weapons just as they strike a foe. All melee weapons you are carrying when the spell is cast deal damage as if one size category larger than they actually are."

That means Lead Blades only affects melee weapons, that you are carrying at the very moment that you cast the spell: Lead Blades doesn't affect any weapons that you pick up after casting it. Since you do not carry the magically created swords from Storm of Blades and since you cannot cast Lead Blades in the middle of the Storm of Blades spell either, both these things prevent Lead Blades from affecting the swords from Storm of Blades.