I hope that Egwene's Tower will have a lot to do with giving the death blow to the sul'dam/damane system, once word that the Empress and all the sul'dam are channelers.

Personally, even though I would have condemned Rand if he balefired them, a part of the reader in me that just likes a good story with large stakes, would have cracked up if he balefired the Seanchan. But that would have caused more chaos as the nations under Seanchan control fell apart with no central authority.