Seems they're close to or even a little over three years old based on what Dio's Event Board shows. At least the change involving the intelligence stat is, which I always thought was the oldest one of the changes mentioned in the above list. Yup. My bad.

As an aside, I still maintain that 'kick' should be lowered from level 9 to level 5 or 6 in this class. Eheh. Honestly.