There's a quicker way which is:
Make sure you set the channel strip's input format to mono.
Command + Option + click the region to Marquee-select it.
Command + Shift + click a bit before the region start or a bit after the region end to extend the Marquee selection.
Press Command + J to join.
It's just two different Logic versions, but it's the same thing.
Basically, Soloing a track means muting all other tracks, but it does not mute tracks that are solo-safed, so that you can hear the solo-safed track(s) along with your soloed track(s).
Your 3rd party plug-ins are .component files found in one of these two locations:
Macintosh HD/Library/Audio/Plug-Ins/Components/
~/Library/Audio/Plug-Ins/Components/
That's a custom assignment.
The key command is Control + X in all Logic key command presets.
You can also access this function via menu: Functions > Remove Silence from Audio Region.
As a reminder, holding down Control while you choose an item in a menu opens the Key Command Assignments window with that command selected, so that you easily edit its assignment.
If, as suggested by oscwilde and des99, you have set up custom screensets in a template, then you can import the screenset into any other existing project using File > Project Settings > Import Project Settings. Select the template file and you'll be able to choose which settings you want to import.
The feature request (that has been requested for many years) is the capability to rearrange channel strip in the Mixer, from the Mixer, and without the need to have a corresponding track for that channel strip.