ginger1...."Is it safe to connect or disconnect the USB cable to/from the computer while the computer is on, or should I shut the computer off " Your USB ports should be hot swapable ........or in other words ...it's ok to have on when plugging in or out .
"Also, is it safe to connect/disconnect the camera to/from the USB plug while the computer is on? "
YES ....but make sure the camera is powered off.
Double check your camera manual just to be sure .
dl65