You could have different end-of-year dates for each trader...

You should be able to do this (you can't however drop a subtree to a node that's in the subtree itself)

Good thinking - we already planned an svg spike (probably using raphaeljs) :)

Yes, it's all KineticJS, we developed a custom shape for connecting nodes.

Thanks. I liked it, Their should be visual buttons to do what the keys do. Unless there are and i'm just blind. It would also be nice is if you double click anywhere it creates a node that you can then connect to another node.