What a sweet looking bike - nice pickup! My understanding is that these bikes were generally reffered to as 'muscle bikes', as they were tying in with the muscle car wars of the late 60s and early 70s. That's why its got the drag slick, wheelie bars, double brakes etc. I've even seen an accesory from this era which was a parachute to help slow you down, just like a drag car. The best place to find info would be some Schwinn restoration websites or even ratrodbikes.com on their forum.
Thats a vintage truck hand signal. Before indicators, drivers used to indicate with hand signals. Because of the extra szie of trucks and that they'd often have a load, trucks had a hand operated hand signal so motorists behind them could see them indicating! Like thishttp://img28.imageshack.us/img28/613/bedfordrjcolor.jpg