point #3 isnt exactly correct. On most Otis elevators the direction you call the lift with mandates an operation. If opposing sequence of requests occur, the lift doors will close and then re-open. You'll notice the directional light above will switch upon the doors reopening. The only way to prevent this is to hit the manual reset (commonly pressing two 'secret' buttons at the same time).

When working in hotels, I use to request an elevator going down with passengers, jump inside, perform a manual reset and force everyone to ride up with me.