Thank you all for your input, it really does help me to think this thoroughly. Draft, have you seen the lunge video I posted less than a week ago or are you talking about the one from a few months ago?
I would keep working on driving him forward into the bridle. I know that you have been having trouble with him stargazing, but I really think that he won't bring his head down on his own until you get his rear end MOVING. I think it has been suggested by others in other threads, but I think cavalettis would be a great benefit to him. Keep changing it up - some days, a set of four evenly spaced poles, other days more random (single stride then double stride or something), and other days raise every other pole. Anything you can do to keep him thinking about what his body is doing is going to help him immensely. It will help you with the forward (space them so he absolutely has to take a good, full, tracking-up stride between poles), and should get him using his back more as well. They are a great tool for teaching a horse that running around with your nose to the sky and your back all hollowed out is way more trouble than it's worth.