At the risk of sounding obvious, focus on Magic. In armor, look at Defense vs Magic Defense. Some gear does add more to Strength and/or Magic, but not all. Magic will make your spells more effective, heals heal more, nukes nuke more.
And once you get far enough in the game, more and more options open up. Min-maxing isn't really a big deal in this game, once you spend some time in the game, you'll likely find yourself (and pawn) changing vocations to get alternate stats and/or Augments. And you'll likely notice a lot of people forsake optimal gear for "Fashion vs Function".
Summery: if it's got more magic/magicDEF, that's what you want. But don't get to serious about it. Enjoy the game and have fun!