You once said :
but BlueBox is not related to GWT in any way so any other technology/library can be used to create a AJAX API
But then said :
In the current state of the code at least I don't know a way to bypass the GWT completely
Now on the other side there is "SmartFoxServer Ajax API"(refered in my posts as "The AJAX API" - the "the" here is important). This is the API created by me and it's not related with BlueBox in any special way - "SmartFoxServer Ajax API" talks the SFS and BlueBox protocol and thats all. The same way the HTTP server is not related with any of the browsers - as far the browser speak HTTP everything is ok. So "SmartFoxServer Ajax API" speaks the BlueBox and SFS protocol and thats why BlueBox "accepts" it - the same way it will accept any other client that "talks" the same protocol. "SmartFoxServer Ajax API" is translation of the part of the SmartFoxServer AS3 API into GWT module - in other words Java.
So as I say a client side API can be create in any language with any technology as far the client side API "talks" the BlueBox and SFS protocol.
Now about "In the current state of the code at least I don't know a way to bypass the GWT completely" - it's the current state of the "SmartFoxServer Ajax API" not the BlueBox. May be here "SmartFoxServer Ajax API" is misleading - this does not means that it's the only one possible and only GWT can be used. You can write your own using any language and technology you want. But the one I wrote( "SmartFoxServer Ajax API") for bad or good is GWT module written in Java. So if you want to use "SmartFoxServer Ajax API" I'm afraid that in the current state of the "SmartFoxServer Ajax API" code you can't bypass GWT. But you're not bound to use "SmartFoxServer Ajax API" as the only way to communicate with BlueBox so from this point of view - BlueBox is not related to GWT(or any other client side technology).
When I wrote the "SmartFoxServer Ajax API" I have in mind heavy AJAX application - like white boards and sharing utilities, games and so on. I didn't have in mind hand held clients.
NOTE: When I mean "you can write" this means technologically possible. But both SmartFoxServer and BlueBox are protected by the copyright law so about the question "is it legal to write" - you have to consult lawyer.