I have this bag and love it!
I no longer use a neck strap for my camera, just a wrist strap (for security/safety) .
When I don't need my camera, it just 'drops' into this bag through the opening in the top. The bag hangs at waist height and can swing around the body depending on your carrying style.
At WDW I often didn't take the bag off me - just swung it around to my front and then sat on the ride.
Re soarin, - you just store your camera bag under the seat in the netting provided. (Also on Star Tours)