As Wings of the Soaring Wind generates a "massive gust of air" that enables the target to fly, could the gust of air be targeted by a perdo auram spell bypassing magic resistance? If so, what do you think would happen? Assuming the perdo spell was momentary, would the gust of air return (as long as the caster kept concentration)? Would the sudden loss of altitude cause a concentration check?
Any PeAu less than 30 would be insufficient to disrupt the spell. Since the spell is Concentration, a momentary disruption might allow the caster to recover depending on how the disruption was designed. If it was to unravel the spell, then no recovery possible. If it was to make the winds disappear for some time, then the original caster could recover as long as they maintained concentration.
No. If a magus creates a D:Conc butterfly and his opponent destroys it with a D:Mom PeAn spell, it stays destroyed no matter for how long the creator keeps his concentration. The same goes with the "severe weather phenomenon" created by Wings of the Soaring Wind: any D:Mom PeAu spell using the corresponding level 15 base guideline suffices - note that this is probably either level 25 (at R:Voice) or level 30 (at R:Sight) spell.
And I have no problems with it, balance-wise. It's a very specialized, circumstantial attack, and one that's easy to defend against either with a ReCo 5 fast cast defense (Rise of the Feathery Body at R:Per, D:Diam), or with the the same-guideline ReCo10 (or ReCo5+ReVi10) D:Sun effect that most magi in my sagas have on themselves when using Wings of the Soaring Wind to Fly. Because, you know, there are many more things that can knock you out of the sky other than a PeAu Hermetic magic.
My personal favorite side-note for Wings of Soaring Wind is that because the wind is magical, it needs to bypass magic resistance to fly.