OK, fair enough. Flavor text it is! How about a +4 Hide bonus in sandy areas and +12 when buried?
Either is fine. I'd be ok with making the "burying action" be a few full-round actions, like 2 to 4, if you prefer.
Sure, go ahead!
Are we ready for skills and feats?
How about 7 ranks in Listen and 4 in Spot?
This seems like a good opportunity to use some psionic feats. How about Wounding Attack or Rapid Metabolism? Power Attack or Reckless Offense might make sense.
Oh, yeah, you're right, I was forgetting about Concentration. We might as well put all 11 ranks in that.
Combat Casting/Manifestation will work for one feat. As for psionic feats, you're right, we should save those for the underbar psionic version. For the non-psionic version, Multiattack might be good (I think we decided two of the same kind of natural attack counted as two natural attacks for the prereq), and Endurance might make sense for a desert critter. Or Power Attack if we want an offensive feat, since it's certainly smart enough to use it. For psionic feats, I don't think Opportunity Power works, since that's for powers, not psi-ilke abilities. Psionic Fist is good, though. Hmm, how about this?
Non-psionic: Combat Casting, Multiattack, Power Attack
Psionic: Combat Manifestation, Multiattack, Psionic Fist
EDIT: Also, I think there are a couple of typos: Psionics (Sp) should give a caster level, rather than a manifester level. And the Psi-like Abilities in the underbar should be (Ps), not (Sp).