semi - resolved.
i am surprised to see that UNDO is not supported. in creative applications, i consider UNDO to be part of core functionality.
regarding ctrl x: my issue was that i was clicking on the clip thumbnail, rather than the titlename rectangle below the thumbnail. i see now that one must select the clip via title in order to use ctrl+ functions.
there does seem to be bug that i'll describe below, see if you can reproduce it:
1- cut a clip.
2- move to another cell block
3- paste
4- without changing focus, cut the same clip
5- move to another cell block
6- paste. NOTE: clipboard is empty.