Yeah, I'm not worried about it, everyone has real world obligations.
I agree about the approach. For now I think, everyone should tackle whatever they feel like. Then once we have a stockpile of visual ideas, we can all choose what works best.
Before long we will get an idea of who is best suited for different tasks. However I want to make sure that, in the end, everyone takes ownership of one of the design tasks. I think maybe we should share the panels. It would help unite our styles and tie all of the different design task elements together.
Here's a tenative itinerary
Week 1: Ideas for story arc and concepting
Week 2: Silhouettes and thumbnails the design elements
Week 3: Start rendering the choosen ideas
Week 4: Finish the design elements
Week 5: Panels
Week 6: Finals art tweaking and brand presentation
Does this sound about right?