I'm a bit confused on this, but likely should not be.
My scenario: We're staying at the Marriott which is connected to Terminal 1. We'll be flying on AA which is out of Terminal 2. So I get that we will talk from the hotel to Terminal 1 where we will catch the Skyline train.
1. I believe we will check in and do passport control in Terminal 2; true?
2. I believe the Skyline is before any security checks; it is open to the general public; true?