Stupidity: After Cory and Shawn fish Mr. Feeny's watch from the septic tank, he suggests they jump into the lake to clean off. Cory protests, reasoning that it's only 20° outside, to which Feeny dismissively tells them to take a sweater. They then reluctantly abide. Someone of Feeny's education should know better than to allow them to jump into a freezing cold lake. They could both get hypothermia, and they're all currently isolated in the Pocono Mountains with no nearby medical facilities.
Truth and Consequences - S3-E7
Stupidity: This episode shows the school's faculty time-clock to be in a common area of the school. Placing a time-clock in such an area would be extremely foolish, as any disgruntled or prankster student could easily mess with a faculty member's timecard. Not to mention the episode shows Janitor Bud bribing a student to clock him out long after he has left for the day.
Answer: Topanga's middle name is never specified. Considering her sister's name is Nebula Stop-the-war Lawrence, Topanga's is probably something equally unusual.