do you see the people from the tour before you?

Yes each new entrance or room has someone there for crowd control and /or clean up

Yes in some of the rooms

I did see people from the tour before and people from the tour after me passed me. I went in the evening and I could take as much time as I wanted in all of the rooms

Yes in some rooms,some rooms they let u be there like 2 min,and u have to be out,and than later on there are rooms you can be as long as you want ,they have big groups,which I found a problem because I didnt get a chance to take photo or enjoy myself