1. if engine is at WOT, there is no vacuum available to the brake booster. It's going to require 2 feet. and you're going to have to stop it in under 30 seconds, or the brakes will heat, fluid will boil, and you will have no brakes.
2. I have tested this. In a 2.2L subaru, in 5th gear, at 70. You can yank the e-brake all the way past the ratchet stops, the brakes will heat up, then the cable gets stretchy and you can pull it all the way up and back, and the car will then accelerate beyond what the ebrake will do.
3. so to me, it's either to stomp the foo out of the pedal with to lillyfooting around, or a neutral drop. I don't know why we don't hear of neutral drops. maybe the people that do them never make the news.