I think the problem was that when it was all out of character, it didn't matter who posted when so we just went for it. Once it's IC we got into the trap of everyone waiting for everyone else to post. Look at where we are now: Mic and I can't really progress until either Anime gives us something to react to or you as GM posted to answer our questions, and I'm assuming you were waiting for Anime so you could answer everyone at once. Everyone was thinking 'I can't post until XX posts,' and so no one posted.
Frankly, the biggest trap is thinking that we have to take strict turns. Real life happens, and someone may not be able to post. If it's their turn, and we believe we can't progress until they take their turn, then the game is dead.
If a game like this is going to live with a relatively quick posting rate, then there need to be updates. I don't want to sound like I'm blaming it on you kc, because I'm not, but when players are interacting with NPC's like this then the GM has to be the one to keep the game moving. Unless we just start talking amongst ourselves and completely ignored Larsen, the players can't move on without GM input.