@Bubbaforum The concept is interesting for certain, but I don't think it's possible game-mechanic wise to channel an ability and also cast other spells. Bladestorm already denies the use of any other ability to make it trigger the Whirlwinds every 6 sec.
How about making the RE so it changes Bladestorm to allow you to cast instant-cast spells while active?
Another option around it could perhaps be that it applies a buff to you instead, which makes it so you trigger a Whirlwind after you finishing casting a Shaman spell with a cast time (so no shocks/stormstrike) and causes the attack to deal added nature damage?