Urriak Uruk
Gaming is fun, and fun is for everyone
There is a lot of flexibility in the campaign. I like how easy it is to add interludes like that.
I’ve just finished If Looks Could Kill as a prelude to the Enemy in Shadows. I’m replacing Josef in your current section with Reiko the Bargemaster as the PCs built up quite a good relationship with him.
I’m also slotting in The Oldenhaller Contract into the Altdorf section as the players have quite a bit to do there so it would be good to give some combat meat to that section.. I also really want to run Night at the Opera for them later on in the campaign so want Oldenhaller to be introduced earlier as an NPC.
Regarding your skaven NPC if they survive that far… they could be a rival clan trying to undo their nemesis. It is kindly of ironic that a skaven might need to prove its own existence and not be passed off as a beast man. Could result in some quite existential conversations.
These look like some pretty great additions! I'm probably not going to add much more than the Affair, as I think by Death on the Reik the party will likely to overleveled rather than underleveled... WFRP definitely considers anything supernatural like zombies or goblins as deadlier than just normal humans, which 5E does not, so there will be a weird disparity there when I hit it (essentially, the zombies they face are going to be tougher than normal 5e zombies!)
Yeah the skaven PC is a little odd, as he wants to be a "nice" skaven who got exiled for being kind of an idiot. I think a good plan is that the cultists do there best to kidnap, incapacitate, or otherwise incriminate that PC so that it is very difficult for the Graf to ever see or trust him.