A couple of things...

Most small races have a base move of 20 feet, what justifies the skaven being a small race with a move of 30 feet? I would personally either make them medium (first option, since skaven were supposed to be man-sized), or drop the movement to 20 feet.

Also, skaven have a history of using diseases as weapons. I would give them a +2 racial bonus to all saving throws made to resist diseases (including magical disease).

Also, I don't understand why you give them draconic as a bonus language. The Skaven might live underground, but they never had a history of dealing with dragons.

Anyhow, just a few thoughts. Good luck. :)