I always played with an almost full party in BG2, and I had a ranger too!
(I always left one spot to be able to hire NPCs to be able to complete their quests.)
True, the Cautious trait is important, but sadly it only benefits PCs, not Wolgraff. And he could do with a bit more sneaking, for sure
tripleDot: the problem is, you need to raise your INT for your spells to be really effective otherwise they won't do any mentionable damage, they'll have only minimal chance to incapacitate enemies and they'll have long cool-down times. You can make a hybrid character of course, but with 15 attribute points to distribute over 20 levels your battlemage will end up being significantly weaker than a specialized fighter or mage.
As an alternative I'd suggest using (and crafting) scrolls. At least they would not penalize the AP cost and they won't have a failure chance due to low INT. They still won't be as effective as a real mage with INT 20+, but that's only fair. Then again, as far as scrolls go, fighters might profit more from buffs and summons. Physical damage is much stronger than even higher level elemental spells in this game. Using spells like Rain and then Shocking Touch or Blitz Bolt would require less INT and AP to be effective. Of course you need to make sure that your fighter resists the stun effects as well.
EDIT: as far as Sneaking is concerned, it's quite important to raise it to rank 5 if you are going to use it regularily. Going into sneak mode will then cost only 1 AP and the sight cones of enemies would be significantly smaller.
