I agree about the alien being a very standard Roswell alien so you might wanna rethink that concept (if you decide to have any aliens at all in the scene - it looks like you want it to be dominated by technology/structures anyway so maybe they aren’t even necessary?).
I also agree about the visible light. They way it is now it gives the impression of some sort of natural light (daylight, perhaps) streaming through cracks or openings, which in turn indicates that the “ceiling” or hull of the construction is very, very thin. It clashes a bit with the rest of the scene. I like the idea of the light beams, just not their origins.
How about some smaller vessels hovering in the air above the crowd and the light coming from them? The constructure is certainly big enough to hold them! 
/Anders
). Just as long as the the final result reflects your own visual style, I myself have no problem with it.
