Can your follower NPCs die?
Only non-plot NPCs can die. You can bat Olivia and Ethan around as much as you want.
While waiting for more votes, we'll have two bonus updates, starting with this promotional Advent Rising comic that was inserted into issues of a couple of DC comics. This comic covers the section between meeting the aliens and finding Olivia in the Science Wing, but it came out in 2004 so there are some disparities between it and the finished game. (SPOT THEM ALL!!)
[ Main site / Hosted / Mediafire / MegaUpload ]
The official website actually has the entire comic in .pdf form, but it's very low quality. So you can either read it from there right now, or you can download my own, higher quality scans in a zip file off of Mediafire or MegaUpload. It's a very short eleven pages, but I do recommend the latter. Also, the penciller of the comic put the original sketches up on his website, which you can view here.
I love this comic because it's ripe with panels like this:
I'll be posting all six Advent Rising comics over the course of the LP.