Yeah, the one pick per level is what makes a sorcerer's spells limited. Of course, you generally get to pick a couple or so spells each time you go up, one spell from each level. For instance, on reaching level 7, a sorc gets to choose a new first, second, and third level spell.
What's really nice is that you have no worries about missing a spell you really want to have, especially as you get up to the higher-level ones.
Drow, duergar, and deep gnomes level more slowly than most others because of the level penalty. This is of most concern if you make any of them spellcasters of some sort. That really hurts. I had a Drow sorc in my first party; never again! I stick with wild elfs for that now.
Did you really blast your team in the shadow door room? I've done that inadvertantly a couple times myself, though only with one character who wasn't as safe as I thought
Nightowl2