1980s-early 90s. Boy with peculiarly long, flexible fingers apprenticed to wizard...

Coffeemachtspass

Possibly a Darkfriend
#1
...with the same distinguishing characteristic. Perhaps 'kidnapped' would be a better term. Anyway. The master wizard is amazingly, hilariously pompous and has a niece (?) with whom the boy falls in love. Two other highlights are that the wizard sends the boy into a local noxious swamp for magic ingredients where he nearly dies in nasty ways, and the local bartender has an unhealthy fascination with the swamp, to which he writes volumes of flighty love sonnets.
Thanks for any clues!