[Bastiaan]

for the piano, if the tracks are mono, combine them 2 in a stereo-track, and after you did that, and moved the plugins over (stop playback, and drag them on the new track), and copied the automstion over, you can delete the old mono-tracks. If they are two stereo-tracks, then you obviously cant combine them like that. So then you have to use sub-groups. Set the output-assignment of each channel to a bus, (lets say 1&2), create a stereo-aux-channel, and set the input-assignment of that aux-channel to bus 1&2 stereo. Now you can slap your plugins on the aux-channel if you want them all to be affected by it.

You can move channels around in your mixer. Just click on the name, and hold it, wait 3 seconds and drag the fader to the position you want. You see a blinking line or something on the place your fader will appear. Let the button go, and voila, you moved your channel. And everything for that channel is moved along, so including all the plugs, automation etc.

If you are going to use the aux-channel thingy, it is a nice combination with a group. Just put all the "members" of the subgroup in a group. This way you will still have all the audio the way it was when you recorded it, and so you have great flexibility.