Notes on the Aether just started recently, I thought, so I'd doubt it will be over in time. I don't remember when Darque Demesnes started, so I don't know about Elthic. Should I add them to the list?
As far as 1sts, we definitely currently have room for some, and if Boddynock decides to run his sidetrek, which seemed like a probable yes, though he hasn't gotten back with certainty yet, then that would give us another whole adventure worth of slots. You wouldn't really make a character who is 'game-specific', I think, except maybe some kind of Medibarian archaeologist knowledge expert obsessed with ancient history, and that wouldn't be wso much adventure appropriate for the actual adventure as it is the only level 1 PC who would know details about the adventure before it started. I'd just pick a class that the level 1s on this list lack--probably Cleric since we're always low on those. Heck, you could be a Medibarian Cloistered Cleric with lots of Knowledge: History and be that crazy archaeology expert too

That'll be just like my Medibarian Cloistered Cleric next level when she takes 5 ranks in Knowledge History to get the Lore synergy.