Listen to the Kobold please.
From the PRD :
Alchemist's Fire : "You can throw a flask of alchemist's fire as a splash weapon"
Swarm subtype : "A swarm takes half again as much damage (+50%) from spells or effects that affect an area, such as splash weapons". (Specific call to splash weapons, not splash damage)
Note that the language implies that splash weapons are effects that affect an area by themselves, and not by virtue of their splash damage.
This is further reinforced by the fact that said splash damage is never reffered as an area of effect in the whole description of splash weapon, but more as as a specific mechanic : Throw Splash weapon.
The fluff section is also pretty clear on the area of effect component of a splash weapon : "A splash weapon is a ranged weapon that breaks on impact, splashing or scattering its contents over its target and nearby creatures or objects".
Any reading leading to the conclusion that splash weapons deal 1 splash damage to swarms on a direct hit contradict both the words used and common sense.
It's 1d6x1,5 for your typical alchemist's fire, and you can target the swarm.
Also, while it is an unfortunate omission for those coming fresh to Pathfinder, PF stays backward compatible with 3.5, so torching swarms should still be viable (and encouraged). I certainly allow it.