Thinking about a few more things that might be good to have- Have you considered making a printer friendly version of this? Its not necessarily immediately important because this is still in the Playtest phase, but I'd love to be able to print it out in black and white without worrying about the entire page color turning gray.
I'm also still a little bit stuck on players tracking their own threads thing too, though. If we're all sitting in different positions around a table, it would be pretty difficult for everyone to be able to see the index cards regardless of position. I feel like it might be helpful to have a master thread list for the GM, and then the players can do the actual tracking on their own index cards? Just pondering.