This shortcut plays and fast forwards a clip
L
This shortcut key sets the "In" Point for a clip
I
This shortcut will bring you back to your default tool.
A
You press this to pause a clip
K or Space Bar
This shortcut key sets the "Out" point for a clip
O
This shortcut key will help you undo any action or edit you just made.
Cmd + Z
This shortcut can pause and play video, but not rewind or fast forward
Space Bar
This shortcut gives you a tool that can slice, or cut, a clip at the frame where you click it.
B for the blade tool
This shortcut key will close out the FCPX software.
Cmd + Q
This shortcut will rewind a video, and if pressed repeatedly will rewind it faster.
J
This shortcut key will turn off and on the snapping feature, which enables your playhead to "snap" to the end of clips.
N
This shortcut key will copy the clip, transition or other item that you have selected.
Cmd + C
BONUS QUESTION
This shortcut key will activate the zoom tool. These keys will allow you to use the tool to zoom in or out
This shortcut key will open the import window to import new media into the project.
Cmd + I
This shortcut key will paste whatever clip, transition or other item that you have selected.
Cmd + V