I wouldn't recommend it, personally. Grinding can be so boring and tiresome, and it really is not necessary. If you want to grind, I would only do it when you hit a brick wall, i.e. a particularly difficult boss or something.
I donít even know what grinding would do outside of unlocking an ability. So much of your stats and abilities are derived from the weapons you have and not stats that itís irrelevant. Iíd only grind if I was one or two levels away from unlocking some key ability but even that I probably wouldnít bother.
I would honestly suggest doing the hardest mode you can and grinding when you need. Part of enjoying the game is focusing on learning the new abilities and spells, and gathering the treasures and equipment around the world. This gives you more incentive to actually do the game. Of course, if you are just playing for plot go on easy. I also recommend choosing the rod and giving up either the shield or the sword as your spells become awesome in the end of the game and you can always grind stat up items for everything except MP.
He's a god, so he has one weakness, he's overconfident. - My Brother