Oh, I didn't go Lone Wolf. It makes a big difference - Lone Wolf/Glass Cannon is a net gain in HP, while Glass Cannon on its own puts you at 1/3 of your normal HP on hard mode (from 75% to 25%). I think my fighter had 60-odd HP when I picked it up. Now that's a glass cannon for you

Stealth kept her out of trouble for the most part though. As far as I know fighters don't get any vitality bonuses, just heavier armor if you spec strength. And you're right, they are terrifying damage dealers!
As for shields and defensive spells, seems like I'm the only one here who loves them! I see them as a more efficient way of healing in combat. One heal might net you half your health over three turns, but a single shield gives you 100% of your health immediately no matter how much you're missing, extra resists, a status immunity AND a status effect when people hit you. And you don't even need high int.
Back on topic, I didn't get much of a chance to use the cone spells. I'd be interested to hear whether you find them effective. Winterblast, at least, looks pretty good on paper.