Tried to get rid of the addict – couldn't. Decided to approach the problem differently:
Using the editor, I removed the addict from the map (left only his traveler boots, as I really like them), made the town he was in neutral – I'll have to capture it on the first turn, and I'll see what happens.

I'm not posting the resulting map yet – both for ethical reasons – it's not right to post someone else's map, and I don't know how playable it will be in general.