So far this is looking like a ranged version of setting sun with bull rushing instead of tripping which could be interesting for martial battle field control. You do definitely need more damage based abilities. I will try to list abilities that I think would be interesting.
The 8th level stance should definitely just give a fly speed and maybe some airborne bonuses like a minor windwall effect.
A good ability to add would be a swift action strike which bullrushes an opponent towards you.
An ability that knocks everyone towards a point in space.
An ability that slams people into the ground with a blast of air.
A reduced version of defenestrating sphere (spell compendium).
The wind shell stance should give immunity to wind effects.
Some sort of windwall effect as a counter.
Some stuff which uses the wind effects
http://www.d20srd.org/srd/weather.htm#tableWindEffects.
The updraft maneuver should have a result based on the bull rush result or have higher versions, these would be useful as they would cause falling damage.