I'm really enjoying where this is going, though with all the stuff that's been mentioned it might be best to revert it back to a 10-level class a la 3.0.

I'm definitely in agreement about being able to TWF better with two, which is why I mentioned a +1/+1 at each level when fighting with two weapons...which when added to having a light weapon in the "off-hand", that would end up as a +3/+3 bonus in a five-level progression.

I like the idea of doing full damage with the "off-hand" by having a feature that basically states "when fighting with two weapons, the tempest is so _____ that both hands do full damage and is no longer considered to have an 'off-hand".

To add to the movement capabilities, you'd almost want to keep the required feats the same. What about gaining Travel Devotion as a bonus feat and additional uses of it as you progress?

Lastly on this post, I like the idea of a cascading damage bonus for consecutive hits.