[Nerull]

1. Rasheman and Thay are bitter enemies. The mages of each realm are bitterly opposed to each other. This is not explained in the game, just in Forgotten Realms literature. Though they never explain why Edwin is hunting Dynaheir, more than likely it can be traced back to this conflict.
2. The Thavians have a strong superiority complex as a culture. They look down at everyone, and see themselves as the greatest mages in the Realms. And the females can be mages just as well as men in their culture. Thus, I doubt Edwin's attitude has to do with hating women as much as hating everyone else he sees as "inferior" to him and his culture.