If playing a ship with linked actions, such as Darth Vader, does the decision to use the upgrade "Advanced Sensors" prevent you from doing any linked actions? The upgrade says that you can do 1 action?

It does prevent you from performing another action but not because of the "1 action" clause but because of the second half of the card that explicitly forbids you from performing any other actions during your activation. If you have a way of performing actions outside of your activation, by being coordinated by another ship for example, you would still be able to perform those.

"you cannot perform another action during your activation"

That's it, you get the one action after you reveal and no more in your activation phase. (cannot also overrules all other rules so there is no way around this limitation)

6 hours ago, Icelom said:

That's it, you get the one action after you reveal and no more in your activation phase. (cannot also overrules all other rules so there is no way around this limitation)

The only way around this is to perform actions outside of your activation, thanks to a timely Coordinate or similar effect (like Airen Cracken ).