Cut and paste work just as they do for the Sketch editor. Select the Pointer subtool and highlight the controls you want to copy by dragging or shift clicking. Then use Edit>Copy (Ctrl+C) to copy what you have selected. You can then use Edit>Paste (Ctrl+V) to paste the controls into another screen or the same screen they were copied from. Unlike the regular sketch tool you will not be queried to see if you want to replicate structure since there is not any structure to replicate: the controls will simply be copied verbatim.
To copy an entire screen just use Edit>Select All (Ctrl+A) followed by Edit>Copy. All controls and comments, including all hidden elements, will be copied.
Copying will also place a metafile in the clipboard which can be used by other applications. This is unlikely to be of any value however, because the screen does not appear completely the same as it will in the running Venapp.
