OK, a couple questions.

I've played a little single-player (the game seems promising, but there also doesn't seem like there's much of a story, and the enemies seem repetitive so far) and some split-screen co-op. My friend came over after I'd played for an hour or so and gotten my soldier (Roland) up to a level five, and she joined as a new, uh, well, Brick, whatever that class is supposed to be called. We went on to do some quests and play for a couple hours, but we kept seeing messages that she (Brick) was ineligible for any of the quests. She got xp and leveled up just from the enemies, but the quests seemed to be off-limits. I thought Borderlands was supposed to be a drop-in/drop-out kind of thing. What gives with the quest thing?

(And why the heck did they have to cut off all peripheral vision and do vertical splitscreen???)