Exactly what your problem is, quite honestly I don't know. You could try to
have a look in sys.endpoints and sys.http_endpoints and see that everything
looks correct. And by the way, http endpoints do not use IIS, they just
reserves the URLs, so that IIS cannot use them. Http endpoints works
perfectly even without IIS installed, what they do use however is http.sys,
which is a standard OS component.
Hope this at least helps somewhat, and if you still don't get it, perhaps
the records form sys.endpoints and sys.http_endpoints may help me or others
to see the cause of your problems.