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.
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.