Here are a few keyboard shortcuts that I’ve found helpful.  These are the default keyboard shortcuts, not key mappings or bindings:

• Hit [Ctrl]+U twice to reset the User Interface.  This should be the first thing you try in order to fix common UI issues.
• [Alt]+Z hides / shows the User Interface (great for taking screenshots)
• [Ctrl]+[Shift]+F shows your frames per second. It appears as very small green numbers in the bottom left corner of your screen.
• The Z key will cause your character to draw/put away their weapon.  Hitting Z while running will cause them to run with their weapon out.
• [Ctrl]+Left Click an item allows you to preview how it looks on your character.
• [SHIFT]+Left Click to link an item into whatever active chat channel you have selected.
• The N key opens your companion window when you are on your ship.
• The tilde key (~) will open your companion’s skill tab.

• [Right click] = companion gathers.  [Shift] + Right Click = your character gathers.

• [CTRL]+S mutes all sound.