You can stretch automation by using automation items. Can also compress/expand by using Amplitude parameter in automation item properties. For skewing on the edges there are no mouse modifiers, but there are some actions in SWS extension:
SWS/FNG: Shift selected envelope points down on left
SWS/FNG: Shift selected envelope points down on right
SWS/FNG: Shift selected envelope points up on left
SWS/FNG: Shift selected envelope points up on right
EDIT: I just noticed that the above 4 actions unfortunately mess up the volume envelope if it's in fader-scaling mode
Reported to SWS issue tracker.