I've argued for Wulfhart against those who saw speaking with him as pointless - now let me do the same for Uzkulak and the Moulder Combes.
During this entire next stretch of the expedition, our most likely foes are Clan Moulder and the Chaos Dwarves. Being able to intercept any Skaven plans to attack the expedition will be a massive boon, and there's unlikely to be a better chance to see what the Chaos Dwarves are planning for us than listening to the scuttlebutt in the Uzkulak markets.
With the Keeper of Secrets having headed east, the priority for checking on these areas only goes up - if we can find confirmation that the Skaven or Chaos Dwarves killed the KoS, that's valuable, and if instead the KoS has linked up with one of those faction it's even more valuable.
Dismissing them as "side quests" is deeply misguided, in my opinion - this is one of the best information gathering opportunities we'll get for quite some time, and both of them are directly relevant to the expeditions interests.