Sorry one more question. How do you get the mixer channels to group themselves? Like all the FX channels together in one place? Thanks!
Effects channels and group channels should group themselves under their named folders automatically.
You have to change their order in the Project Window, then they will change in the Mixer.
The long requested ability to change the order in the mixer separate from the Project Window was not a new feature in 12.
You can however change whether they are on the left, right, or center in the Mixer window from the left pain with the little dots. The left and right will ALWAYS be visible though, and the center can scroll.