Thank you so much for your reply!
I would add a fourth type: the heretic. That would be similar to your pondering atheist, but I see it as someone who rejects creeds rather than someone who rejects God.
Sadly, the terms "heretic" and "gnostic" and "infidel" are thrown around by many who believe that their own doctrine is absolute. Some, like the Islamic extremists, even kill over it - thinking that all who do not see things their way (including some other Muslims) are infidels not worthy to live. When I use the term "atheist" I am speaking to those who deny God altogether.
An "intellectual agnostic" to me is one who has unresolved questions. And to those who would be inclined to dismiss agnostics as "lost" - I would remind: doubting Thomas was an Apostle, too.