The twist is certainly interesting and deserving of further detailing. There could really be more information on this witch and why she bears sucha grudge against said villagers that she is willing to turn their children into livestock and then have them returned.
I dont know that the troll is that important to the story since a foul tempered outlaw, or village pariah would do equally well in the instance of a courier since a troll is likely to attract undo attention. More background, more details, and perhaps a plot hook on how the PCs could be drawn into this rather than killing the troll and 'stumbling' onto the secret.
I bet the final version of this scenario was fun to play, it seems like a good idea. Sure it borrows heavily from a certain scenario from a certain computer game (Icewind Dale 2 was it?) ;) but I like it anyhow, it has been altered sufficiently to not resemble the game too much. Other than that, I agree with the others. Go to Comment
Somehow, someway, a band of gnomes learns how to be ninjas. In fine gnomish style, they open an academy to teach this art to other gnomes. Wacky Hijinks ensue. Or the gnomes become some of the finest assassins in the land. Or both.