If the cover has Ayane on the front, it's 3.1. If it has Christie or Jann Lee in the front, it's 3.0. If it's anything else, it's 3.2.
No. An easy way to tell if it's 3.0 is take Hayate and throw (F+P) an opponent into the wall. If you CANT hit the opponent before they fall to the ground then it's 3.0. If you can, then it's 3.1 or 3.2.
If it has Christie or Jann Lee in the front, it's 3.0.
If it's anything else, it's 3.2.