Anti-bugout feature?

In my experience so far, i've had a few members of my party that arent guild mates bug out halfway through a mission.

Would it be possible to have that person be replaced by a NPC of the same class? or possibly even a feature that people in the town can hit "Instant action" and they can join a group of guys that is currently playing and short a player because of a bugger?

The instant action thing could be stupid, and prevent people from actually doing their quest. But, i think replacing players that leave mid quest with NPC's would be nice.

Speaking of quests. I'm not much of a option browser; but, is there a option to open a quest log that you can edit? like, a little notebook to write down information that you need? I find it kind of hard to memorize what the NPC's are saying all the time...

Well the "insant action" thing could work if you disable exp gaining for those who join the mission later on, to prevent freeloaders.