Is this from the BWB? I know all AS could channel. But I didn't know that all channelers were asked to become AS.

'Going to train to be Aes Sedai' and 'learning to channel' were considered synonymous because of the pervasive nature of the institution. And yes, that's mostly from the BWB, though we do have hints from the books such as the quote Luckers referenced, Forsaken thoughts, etc.

However, that doesn't change the fact that - having completed the training - AS were apparently free to pursue whichever career they saw fit.

Indeed, it does not. Most Aes Sedai had professions that had little or nothing to do with the Power. Be'lal was a lawyer.

Hence Semirhage's choices were not simply dictated to her because she had a gift for Healing. She was a sadist (Ooh! So hot into the bargain) and picked a profession that let her research and indulge her little whims.

Hence Semirhage's choices were not simply dictated to her because she had a gift for Healing. She was a sadist (Ooh! So hot into the bargain) and picked a profession that let her research and indulge her little whims.

It was not dictated to her, but in the Age of Legends, honor was a currency of sorts. Everyone's goal was to earn the third name, and Restorers had one of the most highly respected professions. Semirhage was highly honored for her talents.

Yes it is the perfect profession for her.