Wow, those are all a lot of great ideas!
First with the Gray Maidens, I'm definitely going to go the happy-sunshine route. Maybe there will be a darker tinge to it all later... I actually really want the PCs to be on Ileosa's side for as long as possible (I think that they wouldn't care for Eodred much, and I love the idea of them being loyalists during the riots. Much more potential for conflict)
I've also started working on an expanded intro:
The PC's show up at Zellara's and she tells them the story about her Harrow deck and her son. At the end, she says that she's used her deck to discover that her son had an accomplice in finding Lamm. She tells them of an inn/house/tavern where the accomplice can be found. They arrive (getting a chance to see a social side of Korvosa), then ultimately find out that the accomplice was his lover and that she's either (a) gone into hiding or (b) joined the guard. I'm leaning towards the first option, since it opens up the potential for some light combat (fight off Lamm's thugs when they get to her). She'll tell them where the fishery is-- perhaps they'll convince her to join the guard (or at least go to them for protection). That way, there can be a female guard member that they have more of a connection to who can eventually become a Gray Maiden.
At the fishery... I can't decide if Graeden should be there or not. If not, there can be an underling and it all leads to Knick's awesome-sounding shiver-lab encounter later in the adventure. If he is there... he could run away (cue shiver-lab), or they could kill him and find a letter from the King of Spiders (turns out Gaedren's been working for Barvasi all along??) That way, Eel's End has more of a personal connection and they could have more of a mission to "take on the underworld." If he does escape, where are you putting him in the end, Orthos?
I'm definitely going to try to use Rolth deflect attention from the queen. I've also read of someone tying him into Gaedren. Any ideas on that? Or does that just make everything too connected?
And once again, thanks for the ideas! My campaign is getting more interesting by the second!