How to make keyboard shortcuts work with Command instead of Control ?
Inkscape runs under X11 and is originally a Linux app, so all keyboard shortcuts are based on Control and not Command as in OS X. For example, Copy is ⌃C and not ⌘C. You can use an “.xmodmap” file to switch the behaviours of Control and Command in X11 applications. See above how to create and open the .xmodmap file.