... I would want to set my mouse button 4 or 5 to automatically start launchpad...
I got it to work with Button 4 on my mouse. I set my Launchpad shortcut to control spacebar. Then I wrote this applescript.
tell application "System Events"
key code 49 using control down
end tell
Then I went into the prefs of USB Overdrive ( a mouse prefs add-on I already had) and added the apple script to Mouse Button 4.