The following is pulled from an email by the GM, responding to a question about changes he made to the campaign. I diverted from the adventures as written for two reasons. Primarily, a p:Brian:player] and dear friend of mine left the game at the end of chapter 6 to move to a different state. The party was very much a cohesive unit, and the loss of the player couldn't be explained by "his character got bored." So, I ended up killing off his character in sort of overly dramatic way that (to be honest) I now regret. It caused one of the other characters in the team (his sister) to leave, and that player took over an NPC as her character. (Shensen_Tesiril, the drowish adventurer with the Striders_of_Fharlanghn).
The character that killed the PC was Kaurophon, the stunty little nobody that the players are supposed to gack with ease at the end of that chapter. He instead became the game's main villain, and the climactic showdown in the Fiery_Sanctum at the end of Chapter_Ten:_Thirteen_Cages was against him in my game, not Dyr'ryd.
Other changes were made based on the fact that things seemed overly gamey to me. For example, my players caught on to the changing mood of the town very early. The authoritarian regime Vhalantru was putting in place ticked them off, and the idea that the PCs they'd come to respect would just sit by and take it while this happened was repugnant. So, I introduced a somewhat lengthy plot thread about a rebellion against the city government.
Arguably the biggest change I made to the game was the fact that the volcano didn't erupt. If I could suggest a single change to the game, to be made by everyone playing the game, it would be this. Placing the damn town in Volcano, and then having the thing actually erupt, is not clever forshadowing. It's stupidity. My players were urging people to flee town to escape the impeding eruption by Chapter_Three:_Flood_Season. The emergency that caused the evacuation of town in my version of the game was the planar conjunction itself, which caused huge imbalances within the town and actually teleported parts of the outer planes into the city. The stresses on the ground and the resulting mayhem should be more than reason enough to use many of the written encounters for that chapter 'as is'.