In response to your questions,
The wait was not bad. It took a little over two hours including entry, parking, going through the process, leaving the parking lot. They ran four queues with appointments at 15 minute intervals for each group. The groups were large. Maybe a couple hundred folks in each. When you showed up, you got into the queue for the time of your appointment. We got there early so our queue was the latest appointment time of the four. We now know that we don't have to get there quite as early next time. You waited in queue until your group was released into the flow. We were released less than 10 minutes after our appointment time, which was not bad. After that things moved steadily through ID checks, temperature checks, health review, the shot, and a 15 minute wait at the end to make sure there are not side effects. I think you can move and register from your new location. The registration would be for the second shot. I don't know for sure since the rollout is still locally controlled. Some folks had chairs with them. They were only need during the initial wait in the queues. Most folks did not have, or need chairs, but there was ample room if you did. They kept folks separated.
I like the idea of drive through. That is what they are doing at Dodger Stadium for the folks in Los Angeles County. I am in Orange County near the Los Angeles County border, so we have Disneyland and SOKA University. Disneyland was walkthrough. I am not sure about SOKA. I was not sure which type Disneyland was going to be until we got some info in the morning from someone who had been there. There were a large number of portable outhouses on both ends: the beginning where the queues were, and at the end in the post shot waiting area.
The key to limiting wait time and creating order is that appointments must be made. Appointments for our county were managed using the Othena medical app. We register in the app and were put in a virtual waiting room. We were then told to check daily to see if appointments were open to be scheduled. We waited for a little over two weeks and then got an early morning email that we could schedule. Appointments were opened for that day and the next. We signed up for the first available. This method avoided the long lines you get with first come, first served, which would not work with the millions of folks we have in our area.