I don't think @doctorbadwolf wants to "stick to canon" as much as they want to use canon as a jumping point to create a compelling story.Not wrong, but extremely complicated if stiking to canon. As I said earlier, if I was DM and a player had this concept, I'd change canon. I was trying to think within the parameters set in the OP, which makes for a steep climb.
About the open lord... She is a centuries old elf. Even if she is good, she has to be disconnected to the plights of the young and poor of waterdeep. Disconnection from their people is a great way to fuel a rebellion, no matter the leader's alignment.