Okay, this idea may mainly be based on silly nostalgia, but how about putting an area a bit like the Warden's District in between main Mistlocke and the camp of the Companions? One without NPCs in it so there could be an open area for ambushes, duels and banditry there. It could be a stretch of woods with open areas and pathways, or something like it, or maybe just some abandoned huts and infertile fields. Add in some patches of Mist for spookiness and poor visibility and it would be an excellent place for all sorts of shenanigans.
Small edit: WC pointed out that this already exists in the form of Crossroads/Scars, but my point is, this new area would make it impossible to just go the 'safe' route between Mistlocke and the transition next to the Tower of the Gods. No risk free travel when the DMs are busy. Of course, the same effect could be achieved just by closing that transition off.
Even more edit: It occurred to me that blocking the 'safe' route off would not be quite ideal as it would mean a guaranteed intercept for lurkers between Mistlocke and the Camp in the Crossroads. In Ye Olde Days, we had at least four or five different ways to get from Docks to the Duchy. Maybe a tunnel route from the Tower of the Gods would help, or a passage from the southern Tear area, or both.