TSA Explained (Hartsfield-Jackson International Airport Atlanta) 

International terminal

Yes, there are signs indicating the Sky Priority lane. Usually there is a TSO checking your boarding pass before you get to the lines. HIs job is to make sure you go to the correct line.

The rules change sometimes. The general rule I follow is to use a few bins as possible. But laptop computers must go into a separate bin. However, it is possible that rule changed also. As I said, I use as few bins as possible. And if there is anything "wrong", the TSO will tell you an item needs a separate bin.

If your liquids are under the permissible amount (3.4 oz) then they can stay in your bag but it’s probably still best practice to take them out.

And if your bag gets flagged, it gets redirected for secondary inspection, where they go through it thoroughly. Sometimes they take it back and run it through the x-ray again. There are at least 2 reasons your bag gets flagged: 1. The TSO sees something suspicious during the x-ray scan; 2. it was randomly selected. It's no big deal. If you have a container that holds more than 100ml, then they'll let you throw it away.