Regarding lore skill, I prefer to have 1 skill point spent on it, by my main mage, then have personality trait that adds another +1, and then use any two rings and amulet that add +1 lore each.

That all together gives total of +5 to lore, and I actually think this is really useful in combat, since your character will know what kind of resistances each enemy has. Even better if this mage has biggest initiative, so you'll know at start of the combat what to do. Although this could be tricky if you plan is to use such mage with leadership (which gives initiative to other characters). You could focus one mage (like Jahan) as loremaster and other mage as leader, or vise verse.


P.S.
Personally, I'm not fan of glass cannon. It makes easy fights even easier, but does not help that much with tougher battles in my humble oppinion. Definitely something I would avoid for 1st playthrough.