To both of you, don't worry so much about the stat growths while leveling. It's not completely irrelevant, but, gear just matters
so much more in the long run. Sitting at max level I have no trouble murdering stuff with magic or melee, and I never ever bothered to min/max my stats at all. I've said it in 2 different posts over the past couple of days, but, when I can use one ability to remove 2 full bars of health from a cyclopes in BBI even if min/maxing gave
noticeable damage differences (which it might, I dunno), those cyclopes only have 11 bars of HP anyway. Doing more than I did now would just be stupid overkill. Just swap your vocation around, get the best gear you can afford, and don't think too much about it.
Also as quick math, what you said about your pawn Erehael means that you only lost 140 defense by playing as mage/sorc as opposed to warrior or 210 compared to fighter (assuming I didn't fuck up simple math there, which is entirely possible given my inability to do simple math). Anyway, the second best chest piece in the game for warrior/fighters (which isn't that hard to get once you start farming BBI) has 202 defense fully upgraded. That one single piece of armor is about the same amount of defenses you lost over the course of 70 levels, which, is minimal when you consider you have an entire armor set to equip.
As for a walkthrough for platinum, I used
this one myself. Specifically I found the way they structured the quest achievement to be extremely handy. They use a color coded naming system to show when each quest is available at each point in the game.