Thorax is an ally - he seems to be perpetually scared, but will act as a distraction if you need him.
Smooze... the old, 1 generation one would be an old one - I remember trying to get you to stat him. The current one is a relatively friendly, but obliviously destructive gelatinous moron, who grows from consuming treasure, and is immune to most forms of magic. He (it?) is never purposefully harmful but will try to eat interesting objects, and when grown, might accidently engulf ponies who don't get out of the way.
The cursed items (I've just remembered one more):
Alicorn amulet: a large black iron pendant with a ruby - it gives a serious boost to the wearer's magic, but affects alignment, causing growing megalomania. Can't be removed against the wearer's will.
Inspiration manifestation: a "book" made of two connected stone tablets, with a single poem inside. Whoever reads it aloud gets the item's power (basically, permanent greater creation/ polymorph any object at will) but develops a growing obsession with making things 'pretty', combined with rapidly deteriorating taste. Breaking the curse is relatively simple - someone she cares about must built up the courage to tell her to her face what mess she's making. However, the changes already in effect need to be dispelled separately, and the book seems to be able to come back elsewhere if destroyed.
Love poison: a love potion that's disturbingly easy to make - once consumed by two ponies, it causes them to fall for each other, obliviously and obsessively. The effects pass, but during that time the ponies will only care about each other, and exhibit hysterical strength if anyone tries to separate them.