Yeah, you don't need to be in the drops. You can get just as low by bending your elbows. I've tested it in 27mph crits, one lap on the hoods, one in the drops, etc. etc. and had no variance in performance. I do prefer the drops for comfort. I agree though that it's nice to pick up the extra wind -- I do that a lot on steep descents.

Regarding front/rear braking. When you're in a corner, the front tire provides "x" traction, and the rear provides "y." Some of that traction can point into the corner, keeping you from sliding out, and some of it can point backwards, slowing you down.

Since your center of mass is above the ground, when you brake, "x" goes up, and "y" goes down as weight is transferred to the front of the bike. If you're using rear brake, it's much more likely to lock up and slide than the front wheel. If you use the front brake, all the "Y" traction can be pointing into the turn, while the "x" traction goes up, and more of it can point backwards.

That said, if you're going fast enough to lock up the front brake, you're hosed anyway. If you are going to slide a wheel in a turn, you would want to slide the rear -- but that's not the objective... you want your tires hooked up.

In general, the rear brake should just be for trimming. In controlled slowing, rear brake is appropriate, and easy to modulate. If you want to play with the lock-up point, practice descending, and over-braking whil you still pedal. It becomes very obvious exactly when the rear brake locks up if you're pedaling. Of course, this needs to be an open and safe course. It is a good exercise though, to push it to the limit when you have control. You can also test your traction out in the rain this way -- just ease into the heavy braking, don't pop it all at once.