Does KX_GameObject have any default properties?

if so can you please list them. And also, how can I get an iterable list of properties from a KX_GameObject?

No, it does not.
Check the API for a description:

KX_GameObject has instance variables, if that’s what you mean. Those are things like “mass” or “children” or “localPosition.”

You’re question wasn’t entirely clear to me, though, so I can’t tell exactly what you meant by “default properties.”