So many responses! Sweet! Let's take things in order.
Okay, yes. The swarm of crow ghosts sounds hilarious. I hadn't even -thought- of a swarm creature. But the save for possession is fixed 15+Charisma, unless I'm missing something, which means it wouldn't be going off very often on important targets. Not that I can't think of a million applications for it anyways, but... Is there a way to fix that?
As far as the ghost-- I've just dug up Otherworldly, and it looks like that'd take away all of my lovely immunities to negative energy, stat drain, criticals, etc, when it made me an Outsider. Am I missing something?
As a general note-- please, please mention a book when you name any class not in the SRD. I can find them through Google, but it feels like a waste of time.
Also, as I mentioned earlier, we have several pixies an a vicious GM. So odds are a lot of opponents will be able to counter invisibility. That makes me leery of the Sylph. Though maybe if I paired it with a Paladin...
For setting reasons, I'll pass on the spell-stitched. But I do like the idea of playing a psionic druid. Thing is, I've never dealt with Shepherd or Totemist before. Can you unpack that build for me a bit more? To steal a line, "Explain... as you would a child."