Yes, you can easily bail on all of the rides, even if it means walking onto the platform for the rides, and passing through to the other side. Just let the ride operators know, so that they don't leave spots unfilled if you're walking through and not staying.
Most of the Universal rides are pretty easy-going, not like roller coasters that throw you about, so you might find yourself wanting to try some. I came back a few weeks ago from our trip, and thought I wouldn't be able to ride most of the rides because I had tailbone removal surgery a year ago, but with a cushion to sit on, I did all of the rides! No problem. The simulator rides were truly impressive, and some of them offer stationary seats.