Well yes that goes without saying.The first thing I note, Rechan, is the lack of an aura, which (I'm guessing without checking every single one) all swarms have.
I'd also recommend that frenzied rending deal the ongoing damage as well, since the swarm's basic attack does.
I'm kinda leery of the "pull down" power. It doesn't make sense thematically unless it's a swarm that naturally would pull things down.Finally, I'd give it either a move action power or a minor action power; look at blur of black from the raven swarm, or pull down from the needlefang drake swarm.
Blur to black makes no sense because all swarms can move through enemies squares. So it's a move action saying "This swarm does what swarms can do when it moves".