Your description of a multiple threaded sandbox game was an enjoyable read and highly relevant. Thoughts for your comments and discussion:
The role of arbiter: my intent in starting this thread was to find a writing partner with whom I could explore character focused stories in the Forgotten Realms. I never expected it to turn into something bigger, but if people are interested, why not? Given the number of people who are interested, the very least we should do is have a shared baseline view of the setting and the other issues Mnemaxa brought up. Like I mentioned, I'm not going to do all the Big Events that throw the setting into upheaval. If my character decides to go to Waterdeep, I would like it to still be there when he gets there! As for major events like wars and so on, what does everyone think about having a OOC/coordination thread? The point would be to let the other writers know before somebody does something big, like a war as Godfang mentioned. This is important because even if no fighting takes place where another character's story is located, there will still be effects: some imports will stop, prices will go up, armies will be marching on roads, and refugees might swarm the countryside. Time is another important thing, having people's stories relatively close to each other in time, within the same month or season. Then again, we could all decide to ignore what's happening in each other's threads and ignore any inconsistencies if two writers decide to have their characters meet. This might be the simplest and the best.
Speaking of having characters meet, that was never my intent, and if it did happen it would be because it had been mutually agreed on OOC. What does everyone think about this? I don't think an arbitrator should have to weave all the stories together. That would be alot of work especially if we are primarily focused on our characters' inidividual development.
Level control: This is a very important point. I mentioned it in a previous post, when I talked about improvement by story activity. I guess the important thing is that characters who might meet at some point progress at a rate that makes sense. Example: a character who spends a year in hard training with the Waterdeep city guard would improve more as a swordsman than a character who kills 10 people in the course of the same year but doesn't do anything else. We have to completely abandon the idea of levels and experience points. Ideally improvement would, as Mnemaxa put it, be a byproduct of the story. Improvement would be reflected not on a character sheet but as described in the story. For my character, I was going to start him at a stage in his development I was happy with and not worry about improvement. I guess it would be on a kind of creative honor system. My comments about development through story arc are also relevant here.
Regarding preference of one thread over others: I suggest we all put our character/story ideas out there and let's see if we can match concepts and interests. I welcome other people's suggestions.