For instance if I run two rebel troopers can I play squad tactics to activate them and trigger guardian on both rebel troopers?

Same for hit and run allowing me to activate a red character as in rebel trooper and trigger guardian. Not sure if it works or not so I just wanted to see what other peoples thoughts on the matter would be!

Thanks for the info!

Yes. When the condition is met, Guardian triggers.

If an action would allow you to activate both Rebel Troopers then before each one activates Guardian triggers.

Thanks! That is how I have been playing it but wanted to be sure!

Yes, the cards allow you to activate the character out of turn, but you still activate.

Technically there could be a future card that allowed you to roll the character's dice without activating (for example), which would mean you wouldn't be able to trigger Guardian.