The danger jar is a jar of random encounters Duncan uses. There should be positive and negative ones.
Troupe of minstrels playing wildly crosses the road through the party picking pockets. Many distractions make it difficult to figure out who is doing what as they dance and brush up against and bump them.
The Innkeeper is actually a ghoul, serving travelers he kills at night as pork.
A runaway mule and cart crashes through the road in a busy street intersection.
An escaped mental patient grabs a character and holds them hostage with a razor to the throat. They make ridiculous demands.
A seller of drugs approaches the party “because they look like the type”. His wares are varied but all make the characters sick for a day and no healing halved until a long rest.
One of the characters is mistaken for a criminal and a group of guards attempt to subdue them.
There is a fire (Inn, campsite, business) and the characters are enlisted to help. Success means reward/reputation? Maybe add in a juicy merchant as a pick pocket target to fuck it all up.
A small raincloud dumps really cold rain the party in a 20m radius, seeming to follow them wherever they go for a while. Superstitious characters may suffer penalties. NPCs may spread rumors and they have to pay more for goods/services. It may be so cold as to cause CON checks or get a cold (Level of Exhaustion.