It is a little disappointing to me that they haven't revisited the power "burn out" that they showed in Season 1 at all. There were clear dangers to over channeling and it's not mentioned since. They also could have dropped in an in-show explanation for Nyn's being healed at the end of S1 and that was sad that it didn't happen.
Aside from Moraine's display at the end of S2, I'm not really seeing a huge power creep among the Aes Sedai. The tower battle felt legit to me, aside from them absolutely sucking at tactics. I can also excuse that, because even the Red's and Greens are more used to fighting stray male channelers and possibly trollocs than other women channelers, especially those who they are supposed to trust.
The healing, while convenient, is also fine. It was also pretty dependable in the books, and you just expected that unless someone had their head chopped off, they were going to get healed. A dude even had his throat cut and head nearly taken off and was healed up by a member of the Kin...so yeah. The books might have started out saying Aes Sedai were weaker than expected, but that changed, especially in the later half of the series.