Copy and Paste works with mouse-curser context menu.
Terminal is in the application menu top left corner.
Try to avoid keyboard shortcuts (sadly). My keyboard input in the VMs stopped working a couple of times, only worked in the proctor chat. A VM reset by the proctor solved the issue always. (not loosing any previous work!)
If all fails CALL THE TELEPHONE NUMBER provided.
Yes, it is possible but just remember to use: Cntl+C & Cntrl+V when you are in a browser and Shift+Cntl+C & Shift+Cntrl+V when you are in a terminal. You can also use right mouse button and select in a pop-up menu or you can use Copy&Paste in a browser or terminal menu. But of course the last 2 methods take more time.
I think, CTRL+SHIFT+R (after selecting/clicking the chat window with your mouse) should reload the exam environment, but it is advised to simply tell your proctor to "reset"/"reload" the exam environment for you instead.
If a proctor is not responding quickly enough, just start shouting in the microphone and if even that does not help, do not hesitate to call the hotline at +1-919-716-5001
And insist on getting the lost time added to your exam duration!!