Is there any major reason why any of these were changed? I assume just so they could be easily decided between in menus on the fly... It's easier to remember what Null Attack does as opposed to Master Canceller. In my opinion, anyway.
There is that, but there is also space constraints to worry about. When each skill name has a six or eight character limit it kind of limits what you can use.(it's not quite as bad as it was in the NES days, when you had names like Blt2 or Hrm... :buh: )