la capacité de l'empereur à tirer les ficelles.

I had to use Google Translate, so I hope I got your question right:

You are limited to 1 attack action "during" your activation. When Palpatine gives you an attack action, it is not "during" your activation. So, yes, you can do an attack action when you activate, and you can do an attack action from Pull the Strings.

Does a free move action given by "Pulling the strings" allow a unit of Royal Guard to perform a "Charge"?

1 hour ago, Scabiosus said:

Does a free move action given by "Pulling the strings" allow a unit of Royal Guard to perform a "Charge"?

Yes, the unit performs a move action, so anything that triggers when it performs a move action like Charge, Steady or Relentless for example, triggers with Pulling the strings too

Thank you!

Does it allow a another friendly unit to disengage out of melee?

The rules say that a unit needs to use it whole activation to disengage and perform a speed 1 move. Can you do this "move" with pulling the strings and normaly activate that unit out of melee afterwards?

27 minutes ago, Staelwulf said:

Does it allow a another friendly unit to disengage out of melee?

The rules say that a unit needs to use it whole activation to disengage and perform a speed 1 move. Can you do this "move" with pulling the strings and normaly activate that unit out of melee afterwards?

No because the only way to disengage is to spend your activation on a withdraw. (Actually Force Push is another way to get a unit out of a melee.)

You could do it the other way: first activate and withdraw. Later, Palp uses Pull the Strings to allow that unit to perform a ranged attack or move.