how to use keyboard in osx?

how does the keyboard in ardour work (0.99/osx)? i’m obviously missing something, cause i just cannot make it work properly. for example: according to [] the “split region(s) at mouse” command should be assigned to “s” key. i select the region, place the mouse (in whatever mode, it’s always the same) at desired point, press “s” key - and nothing happens. and so on. it is extremely uncomfortable to perform every little task via menus. what the hell am i doing wrong?
any advice? thanks!

Ardour definitely needs a way to change key commands in OSX.