Well, I don't want to spoil this for you, don't get me wrong here. I really admit the work and effort you put in your project, but I just wanted to point out that in a common way you would most likely do the technical concept and strategies behind in prior, allowing you to get plain view on how the interface should look like. I always obey the form-follows-function rule here, since it is clearly more profitable to me (as well as every professional I've been speaking yet).
Ensuing from this point of view, I'd be interested in how you decided to manage the asynchronous data transmissions that are required once you're getting into iframes and common GUI stuff (such as window positioning, dimension keeping, user preferences e.g). Right now you're only using JavaScript and referred to your statement about the triviality of implementing server side scripting and databases I am wondering how exactly you planned to integrate this after the interface has been done. Will you allow user login and furthermore preferences storage? This would include a snapshot of any windows and things going on in the GUI, and as we are talking about a passive and non-persistent connection, this could get a real pain in the ass if not well designed.