I'm in an X-Wing, I get a droid, let's say R2 something from The Core Box Set. The One that's not R2-D2. The Droid has an action that allows me another agility die. Is this an on going effect I obtain by having the droid as an upgrade? Or, is this an ACTION that I can add to my library of actions I have being Biggs in an X-wing? It's not really clear.

Also, while I have your attention. Is it correct that I can lock onto a Target as an ACTION every single turn, if that target is within long range, and then spend that lock on the SAME turn during the attack roll to re-roll any dice that I want to re-roll?

Lastly, is the lock an ongoing effect from that lock action, or do I need to maintain that every turn, thus preventing me from using another action, like Focus or Evade?

THANKS!!

Any upgrade with the ACTION: header adds to your library of available actions.

A Target Lock action can be taken and the lock spent every turn.

When you use a target lock to reroll dice, it is spent (discarded).

R2-f2 must be used each turn as your action but it's a bad choice because three agility with no focus is terrible.

Target lock does persist until you want to use it, once you spend it you reroll as many or as few as you want.

If the droid's card reads "ACTION:" that's an action you can take just like, but in lieu of, a target lock, focus, etc.

You understand TL correctly, except that once take, if you don't use the lock, it doesn't replace your action -- you can take a focus or evade or whatever on the next turn. The TL doesn't go away until used, unlike a Focus or Evade cleaned up at the end of the game.