Just throwing alot of ideas around to see what sticks. My group is currently on book 3, after finishing RotRL. I'm meshing in parts of Second Darkness so if you don't want to see any spoilers from either, stop reading.
Book 1 & 2 - I mostly ran this adventure straight out of the book, except adding in the troll kingdom. We started using the rules from the River Nations book instead of the KM rules. I barred the selling of magic items through economy rolls, but added in more economy resources into hexes like spices, gems, horses, ruins full of antiquities, and trade agreements. My group has always been low on build points, generally keeping no more than 20-30 before spending down.
Book 3 - I ended up making negotiations with the centaurs much harder and played up the racial tensions and its really keeping the players on edge, but they have a shaky friendship with them. I dropped in the city of Celwynvian from SD book 3 into one of the bottom hexes (11,3) and the players have heard rumors of a secret elven war. They also found some paperwork where Maegar had ceded the hex to Kyonin. Later after retreating from Vordakai's lair I had V rise up and send armies of dread zombies south into Mivon, Celwynvian, the centaur camps, and all the surrounding hexes to gather up minions. Eventually full fledged war has broken out with Vordakai and Restov has retracted its bridges and shut its gates to the undead plague. Mivon has become an unlikely ally as they have sent an army into the stolen lands to block a pass that the undead have been using to get into their kingdom. A diplomat reminding me of the diplomat from 300 came to the players kingdom and lavished them with gifts touting an alliance as long as they would respect Mivon's "traditional" northern border which is all of the southwestern quarter of the Nomen Heights. This coupled with the land they ceded to the centaurs, the entirity of the Dunsward plains has left them with a narrow corridor of property in the Nomen Heights.
As far as Celwynvian I had the drow stage an attack outside their capital disguised as the elves of the Shin-Rakarath to provoke them into war. Inside the Armageddon's echo I'm thinking about having a shadow of Karzoug be smart enough to create a "realstuff" version of himself, possibly creating a new superpower in the region.
Books 4+ I'm looking at running some kind of sympathetic Nyrissia story where the players can at least feel sorry for her even though what she's doing is tearing their world apart. My players have expressed interest in aiding or starting the Brevic Revolution, one of them is from Orlovski and his family is being taxed into poverty for their seditious actions. I'm also debating running with the Choral in a Bottle ala Vordakai and Nyrissia temporary alliance, which will give a good twist at the end.
I'm not sure where to go with the shadow Karzoug since Xin Shalast is so far away. I'd probably go with the scenario that RotRL hasn't happened yet. My group pretty much skipped book 6 so I definitely want to incorporate it somehow, even if it requires moving it to make it relevant.
Thoughts ideas?
I'd also like to do something special with briar, like heartrenching and sad.