This is not a "minor" character. It has an impact upon its world is notable. It needs work. Alot of work. The write up does nothing to answer the questions that immediately come to mind when you read this.
Not enough detail or interesting elements to make it more than a cliche. Sorry. Go to Comment
This is a little cliche, but not bad. If the gnome was played well, with a spunky personality, the PC's could have some fun with him...as long as the GM doesn't overdo it with such characters. Perhaps he could be hired to build something for the PC's, or decide to follow their group around for awhile. Go to Comment
I must assume that writing the name down, is going to require a craft check or something similar.
I would say that the result of the craft check is the save needed to negate the effect.
I would also assume that for the platinum version to work, the victim needs to hear his name being spoken.... After all, the more severe the effect, the more chance there should be that the assesin is exposed.