1) I guess if I have Renegade Squadron Mobilization as objective in play and I play A New Hope I get to draw one card for EVERY enemy unit that leaves play if I want to.
2) Combat Icons of a type are resolved at the same time, right? So if I can place 3 focus token on enemy units via Palpatine I have to declare which units receive how many of them before my opponent declares if he wants to use the shield on a unit to cancel one focus token.
1) Yes, you can respond to each unit individually.
2) Correct, you would assign the focus tokens simultaneously, and then the opponent decides if he wants to cancel any of them with shields.