First, unbind the left key from the Whisker menu 1, 4.
Open the file:
/usr/share/mint-configuration-xfce/xfce4/xfconf/xfce-perchannel-xml/xfce4-keyboard-shortcuts.xml
and comment out the string:
<property name="Super_L" type="string" value="xfce4-popup-whiskermenu"/>
Next create or modify the file ~/.Xmodmap
: 2, 3
! -*- coding: utf-8 -*-
! http://xahlee.info/linux/linux_swap_control_and_alt_xmodmap.html
! swap Ctrl and Super keys
! here's the default setting on special keys
! xmodmap -pke | grep -P '(Control|Super|Alt|Menu)'
! keycode 37 = Control_L NoSymbol Control_L
! keycode 64 = Alt_L Meta_L Alt_L Meta_L
! keycode 105 = Control_R NoSymbol Control_R
! keycode 108 = Alt_R Meta_R Alt_R Meta_R
! keycode 133 = Super_L NoSymbol Super_L
! keycode 134 = Super_R NoSymbol Super_R
! keycode 135 = Menu NoSymbol Menu
! keycode 147 = XF86MenuKB NoSymbol XF86MenuKB
! keycode 204 = NoSymbol Alt_L NoSymbol Alt_L
! keycode 206 = NoSymbol Super_L NoSymbol Super_L
! Erase existing bindings
clear control
clear mod4
! Map key 37 (left ctrl) to Super_L (i.e. 'cmd')
keycode 37 = Super_L
! Map key 133 (left cmd) to Control_L (i.e. 'ctrl)
keycode 133 = Control_L
! And update modifier settings
add control = Control_L
add mod4 = Super_L
I was able to figure out how to make it happen though; under
Menu > Keyboard Preferences > Layouts > Options >
there were a bunch of toggles for swapping alt, ctrl and windows keys around. My thumb is right where it wants to be now!