Is that the women who formed the WT were not fully trained Aes Sedai, especially not to the levels expected in the AoL.

These women were a remnant. They came together trying to survive, teaching each other and learning together, claiming the title of their former teachers/masters. None of these women would have been taught balefire.

This was the end of the war, balefire itself had been forbidden by both sides of the war. Even the shadow stopped using it.

Traveling could easily have been lost simply because the people far enough along in their training died, either in the war or in the breaking. The WT wasn't founded for centuries after the breaking was over.

Also, remember that the women who formed the Tower actively forced women to join their organization, and if they refused the "rebels" were stilled and executed. So, any woman who thought she didn't want to join a bunch of half-trained girls would have been forced to join or be killed.