Hey, Ron! In the past, when we had 2 or 3 attractions in one building, we had a separate queue line for each. People didn't seem to mind waiting. I think even the general public plans to make a night of it if they are visiting more than one attraction.
I'd almost think that it is easier to do separate queues than one, as that wait could get extremely long. With separate ones, you seem to have more control over the flow of each attraction, rather than each attraction depending on the flow of the other. Say something goes wrong (let's hope not, but it does happen occasionally) in attraction #1 and you have to stop the show...if you have separate queues, then attraction #2 and #3 can continue running.
I'd love to hear more on this from someone who runs one queue for multiple attractions.