FORGET the word "spin"... you will not feel the spinning, you will not be aware of the spinning, you cannot see outside of your cabin. For all intents and purposes, you remain perfectly still as far as the riders are concerned.
The centrifugal force associated with making 5 Gs, in my estimation, would result in the person spilling wearing most of their lunch. You are going so fast that if you were to spill during launch, it wouldn't have a chance to get forward enough to hit anyone else in your cabin. (that's my best guess. I have no actual experience. Even the second time, when two of the people in the cabin voiced concern that they would be sick... they weren't.)
The seats are divided, and except for glimpsing my crewmates' hands when they pressed their "go" buttons, I couldn't see the other 3 riders.