Yes and so have I, I remember them being just as non descript and based in theory as the episodes. Except for Volume 1 Chapter 7 which was pretty ambigous, even with the clues given by Koizumi and Nagato.
Though since everyone here is already on board with the God theory, I probably shouldn't even be bothering to argue this point, its a waste of all our time. My official theory is that she is a human gifted with special abilities, but I'm probably the only one that holds this position. Its like the lines in chapter 7 say:
"Looking at her young and smooth face, I remembered Nagato's "evolution possibility", Asahina's "temporal distortion", and Koizumi treating Haruhi as "God". But as for me, what is Haruhi to me? Just what do I treat her as?"
Well I treat her as an exceptional if a bit eccentric human being with a gift. My theory could change as the novel wears on though.