Neonivek: "Are you sure Bees have "Intelligence" though?"
+They appear to exhibit curiosity about new things near their hives.
+They can learn to do things like recognize human faces and discover explosives.
+They can communicate complex information with each other using waggle-dances.
To me these things demonstrate a certain level of intelligence.
Neonivek: "For example a Bee will attempt to enter his hive no matter how many times it has been rejected (at
least as far as I know)."
That's the most intelligent behavior I can think of in that situation. A worker or drone can't start another colony on their own and will starve if they can't get back into their hive.
Neonivek: "So far they still seem unridable unless you can blind them and get them to fly and steer them somehow."
Maybe if the rider could tell his giant bee mount where to go using a waggle-dance, he wouldn't need to steer it

. As for being unridable, no one's told that to the varroa mite.