Since I am starting up a campaign in MM2 I decided to put together a hex editing reference guide for it much like what I did for MM1. This time I made a much more complete guide as MM2 has much more to it than MM1. If you open up ROSTER.DAT in a hex editor, you'll notice your characters' names in the ASCII offtset. Using that offset, it's quite easy to manipulate a character's data for whatever reason.

The above being said, here is what I've pieced together so far;
http://img.photobucket.com/albums/v288/XaviarCraig/Game%20stuffs/MM2HAX.png

You may have to open the image in like MS paint if you want to be able to the exact markings if your resolution is really high!

Couple updates regarding it:

* max HP - this is actually the temporary max HP
* ??? Possibly HP related - This is the actual max HP value
* max SP - temporary max SP, actual max SP is entirely decided by Personality/Intel
* Gold/EXP - I mixed these two up.
* AC - this the temporary value, actual value is decided by Speed

>>> actual max SP is entirely decided by Personality/Intel
...and level