You need 1 point of pickpocket to enter the thief guild.
You need two points for the quest of the plague victims.

But you can find or buy some items with point for the skill pickpocket.
It's interesting to spare some of your skill points.

[Linked Image from squirrel.ovh]
duplouy.net badsquirrel.ovh
bad-squirrell.deviantart.com