Covering in one piece is a major pain! I used to seal all of my gaps, but when I started doing product reviews, I put so many planes together that I just don't bother anymore - and I have noticed NO difference.

Than being said, as far as your "stiff" elevator goes, how stiff is it? What many people feel is too stiff is really no problem at all. After all, even a freely-moving elevator is going to have an immense amount of air pressure on it when it's moving at 80mph. A "stiff" hinge is nothing by comparison.