Apparently in the full game you can access companion inventory again, so stands to reason you can respec spells. Frankly, I'd rather just 'Command - Drop' the sword and get into Act 1 already.

I compared save times a while back and I was actually higher level sooner in one playthrough by _not_ killing the cambions. The time sink of spending 20 rounds doing 2-3 damage isn't necessarily optimal use of play time.