I agree that they should get a lab assistant (perhaps at 1st level). I also think this lab assistant should be completely expendable in some way which allows the Mad Scientist to save themselves at the lab assistant's expense (i.e. Improved Evasion and/or Improved Cover, but the lab assistant takes all the damage, etc). The lab assistant should otherwise be pretty worthless (i.e. basically a commoner who obeys them). If the lab assistant dies, they should be able to "recruit" another one as soon as they've disposed of the body of the former one, or a day later, whichever is longer... This should otherwise count as the Leadership feat, and prevent them from getting it, much like the Thrallherd class.
