That sort of startled me, because it is catchy and it is in the vein of a "byteball" type of geekcool phonetics.
Amorphous was on
my original brainstorming list (and I had thought of nebulous in the process of thinking of amorphous and
mentioned nebulous as a negative 3 times on the page), but I think you are correct that Nebula is better than Amorphous or Nebulus.
But is that the meaning we want for a programming language? The language is targeted to programmers. Nebula does have a nice sound to it. Are you thinking the programming language is a feature marketed to the speculators also and thus the reason for the geekcool name?
While reading your ideas I couldn't help but think of the Bruce Lee quote - "Empty your mind, be formless, shapeless like water if you put water in the cup it becomes the cup and water can flow or it can crash."
This also hits back on your Zen ideas. Water, like your language is fluid. It has many degrees of freedom and goes where it is directed. It does not resist, it just flows. Of course, fluidity is not restricted just liquids. It can refer to anything that is readily changeable. Anything that is not fixed and rigid.
So two names that immediately come to mind are... Flow and Fluid