Title's a bit confusing, but let me explain. For example, when you meet Lae,Zel, she tells you about Zorru in the Tiefling camp. Without her there, you can't have the convo with Zorru about he creche. Something to think on, is to allow a conversation, perhaps limited and no where near as colorful as if Lae'Zel was there, with Zorru about the creche. Just some general information about it, perhaps pointing in the general direction of the creche. Do this with other conversations as well, so the player doesn't feel like they "have" to take the characters with them for these conversations. Kind of like facing against Spike without Will. You can still question him, just wouldn't get all the information or special conversations as if you had the characters there.