I too prefer LWJGL to other bindings that I've used so far. It has lots of useful additions like the "glGenTextures()" overload and the ContextCapabilities class. Display is also super easy to set up compared to many other bindings.
You might want to look into Scala, Kotlin, Fantom and Groovy++. They are all "functional" languages that should yield higher performance than something like BeanShell, Jython, Rhino, etc.
I've been taking quick paranoid glances at functional programming a while here and there, so I'll look into it.
Then use LWJGL. Seriously, what do you think the 'J' stands for?
I'm sorry. I was not asking you or anybody else to do it, I was asking if it would be possible or preferable over starting anew entirely.