First off, I didn't read the entire thread, only glanced through to get a general understanding of what's been accomplished and what not, so if I repeat a previous suggestion, I apologize. Now, It seems to me, that it ought to be possible for quests to be adjusted so, if in the off chance a important quest NPC is killed be a flying wheelbarrel or some such, the quest could continue. Say you continue on with you're quest lacking the information that NPC gives, but, since you aren't properly informed, you miserably fail. Adds realism, and makes the random occurrences less frustrating, imo. I don't know if this is quite possible, as I have absolutely no modding experience and only a small amount in scripting, but judging from what has been done in mods already, I think it could be done. Just an idea.