It's... pretty bland, actually. Their abilities lack some flavor. I suggest throwing some skill bonuses and other goodies.
Other than that, the feats:
Make it two feats: One for a 1 minute shifting, secong for complex action shifting.Fast shifting
More items, no shifting time extension.Improved item carrying
Okay.Improved shifting
I'm intigued. This could be extremely powerful when you bring other casters with you.Creature shifting
EDIT: Happy Independence Day everyone!