Hi, new to the game and first post here.

In the mission 1 from the Core Rulebook, if Biggs is within "1" of the shuttle do the imparials have to target him ? Seems like a good combo with R2D2...

Yes. Just did this one yesterday. Even with R2D2, you can't really count on Biggs buying you too much time, but he is an annoyance.

Forget R2D2, add R2F2 and a stealth to Biggs. He will be rolling 4 defense dice.

R2-F2 is great for Biggs, and if you can throw in Kyle or Garven or someone to feed him a free Focus as well, he's got an even better chance of surviving a bit longer.