single key keyboard shortcut run-or-raise applications

Solution 1:

There's no direct way to map an Application launch to a key command, but it can be achieved without too much difficulty.

To break it down into its components, you need

• A Service, which can be key-commanded

• An Applescript, to contain the actual launch command

• An Automator workflow, to contain the Applescript

• The actual key-command.

It might sound hugely long-winded, but it's simpler than building your own .plist

1. Launch Automator, from Applications

2. Select New Document, then Service

3. On the left, search 'applescript' & drag Run Applescript to the main panel
4. Replace (* Your script goes here *) with tell Application "Terminal" to activate
   Using activate will launch the App if it is not running, or bring it to the front if it already is. [subsequent Services you generate will use each of your desired Apps in this line]
5. Click at the top where it says 'Untitled' & give it a suitable name. The destination will be already correct for Services.
6. Hit Cmd ⌘ S to Save.
   At the moment I'm seeing a new behaviour I've not noticed before, under 10.11.6 - Saving isn't automatically installing the service. Closing the Workflow window, then re-opening from File menu > Recent then gives the option to install it. ymmv.
7. Go to System Prefs > Keyboard > Shortcuts > Services & find your new Automator Service [probably down towards the bottom of the list under General.
   Make sure there's a checkmark to the left of it, then click none/add shortcut, to the right & add your F-Key
   Make sure your pref in System Prefs > Keyboard > Keyboard is set to use all F1, F2 etc as standard function keys - otherwise you'll have to use Fn/F-key instead.

Rinse & repeat for your other required Applications.

After comments:
Running Services in this way may require Automator to be checked in System Prefs > Security & Privacy > Privacy > Accessibility