i would say Arte usage Modifer and Item Pointer maybe or something of the like. Inf Overlimit/max OL. and something for the hunter strikes...that would be hard i think but eh.
Arte Usage should be fairly simple to do. I remember doing this on the 360 version even via hex editing save files
You can tell right away too with Destruction Field for example for Yuri whether or not you got the correct values modified, damage goes up big time at 9999 uses.
Working on it now. Have infinite Gald/Item Usage atm. Also managed to do have all items, but it's not pretty. Will post in a bit when I get more stuff done.