IDK, that's pretty much Rand's whole thing for most of the series, and neither the narrative, nor the characters who realize what he's doing, are at all approving. And as always, there is a crucial difference between the two of them, is that Rand does it because the goal for which he sees it as necessary is something he has to do, out of obligation or duty. Egwene, on the other hand, does it because she wants the goal. It's her ambition, not her duty, to save the world or the Tower or whatever. For her it's always forward or upward, with only lip service to the idea of nostalgia or missing her roots. It's why she can't even relax and enjoy Nynaeve's talk with Mother Guenna as a thing from her more innocent youth - to her it's all a big waste, because perfecting Wisdom skills is moving backward from where they are. If it's not going to get her the shawl or directly relate to the mission in an obvious way, she has no use for it. In the middle books, the point is often shown or noted that Egwene does not like being reminded of childhood misadventures or anything that reminds her of being less.

That's very clearly the case with her attitudes in book 3. I've come to the conclusion that that is her arc in that one, getting to the point where when she sort-of captures the Black sisters in Tel'Aran'Rhiod, she realizes she does not want to behave as she saw her captors. But between Nynaeve taking off her collar and that point, her judgment about action or danger or the appropriateness of lethal measures is VERY skewed, and she's almost looking for an excuse to do some damage. As you say, it's clearly post-traumatic stress from the Seanchan period, but she's also rebelling and lashing out at Nynaeve for daring to act without consulting Egwene. It's the same point as with the comments about her age - she might have an excuse for the behavior or attitude, but in that case, her desire for, or insistence on being in, control is completely unwarranted and ill-advised.

And she thinks it's more normal or she thinks less of the fact that they start getting political with each other. The tensions with the Wise Ones and her one meeting with Aviendha after she becomes Amyrlin, the secrets she keeps from Siuan after her captivity, it's a lot like encounters between her and Rand before she leaves for Salidar. It's even there with Nynaeve and Elayne and then later with Siuan, once she starts hiding details of her captivity in the Tower from her. Her OTT reactions to anything she doesn't like, and willingness to use her authority or advantages in T'A'R lead to them starting to editing themselves with her, and treating her more like a boss than a buddy.

I don't think you CAN get to know her too closely, because Egwene will just shuffle you off on some pretext and replace you. She trades off Nynaeve for Moiraine early on, dumps Perrin & Elyas for the Tinkers, then balks viciously when Nynaeve is back in direct supervision of her instead of a full Aes Sedai. She is looking to make friends with Aviendha when she is in the Stone, and is less than thrilled with Nynaeve and Elayne starting to click better with each other, and is already gravitating back under Moiraine when they are about to go with Rand, then she replaces Moiraine with the Wise Ones, and then replaces them with Siuan. And then she finds excuses to distance herself from Siuan and put her down, and falls in with Silviana. Even after she's reunited with Nynaeve & Elayne in the lead-up to Tarmon Gaidon, there's awkwardness & distance with Egwene herself imposing formalities even in private moments, whereas in the early days of her reign, she would use the stole to distinguish between Amyrlin-sister conversations & buddy chats. Even something as lending Nynaeve strength to Heal wounded soldiers requires a mini-speech making it clear she is still Amyrlin, even if she can't lead the circle to Heal. Always forward and higher, never a step back. It's actually kind of sad how she braces herself to push back against Elayne's authority as supreme commander, because she doesn't want to end up under Elayne's control AFTER Tarmon Gaidon...when that's not really going to be an issue.