You are almost there. Now install ksuperkey. Have it autostart in your gnome session. This utility redirects the super key. By default, it maps to Alt+F1. It will probably be easiest if you just map /org/gnome/shell/keybindings/toggle-application-view from ‘<super>a’ to ‘<alt>F1’>.
- have ksuperkey start through autostart
- Reset the overlay-key (<super>) to nothing:
gsettings set org.gnome.mutter overlay-key ‘’
- Reset the main panel key (<Alt>F1) to nothing
gsettings set org.gnome.desktop.wm.keybindings panel-main-menu 
- Change toggle application view from [’<Super>a’] to [’<Alt>F1’]
This works. I had the launcher Albert bound to my super key for a while.
If you do not want to loose the Super+a binding, you could directly have ksuperkey redirect the super key to Super+a. Not sure of the syntax required nor of whether it will work.