What's with the swarm-only creatures?

[ShurikVch]

In the game present some amount of miniature creatures which seems not exist outside of swarms.

So, questions:
1. Do they fit for druid's companion/wildshape?
2. What's about possible lycanthropy?
3. What if some form-changing spell cast on swarm? Say, Animal growth? Or, Incarnate Construct - on golem swarm? (And possibly follow with Nar Fiendbond )
4. What's with some extreme templates? Anthropomorphic, titanic, kaiju?

[Namfuak]

1. You could only turn into a rat swarm, the rest are considered diminutive animals and druids can only go down to tiny.
2. Lycanthropes can only be paired with one of the animals already listed, there are no rules for lycanthropes of other kinds in the SRD.
3. Anything that normally works on an animal (or construct, in the case of a construct swarm), should work on swarms. However, changing size would probably not work, as the swarms do not follow normal rules for space and reach based on their size.
4. They would technically be applicable, but see above about size changing.

EDIT: Ah, I see where that line is. I missed it before.

[White_Drake]

Actually, the lycanthrope, or more properly, therianthropy (WotC has always irritated me with that) template can be used with any carnivorous, omnivorous, or scavenging base animal which is within one size of the base creature, so at least rat swarms would be applicable (for small characters). I think there was a thread about a were crow swarm BBEG a while back, although I don't know where to find it.

Edit: Ah, here it is (http://www.giantitp.com/forums/showthread.php?t=242841).