After an engagement and the battle is over, what happens to the unit cards that are left behind on the table? I know the cards eventually get refreshed if they are exhausted, but what happens after the refresh phase? Am I obligated to use the previous cards or can I play newer cards during my deployment phase? In other words, can I use newer cards in battle before I use older ones that are still around from the previous time that I attacked?

NerdRulez said:

During an engagement, each unit involved strikes. The strike is marked on the card by placing a focus token on it. After each side of the Force is finished (i.e. each of their units involved in the engagement has been focused) the engagement ends. If all of your units did not battle in that particular engagement, then you may choose to engage another of your enemy's objectives.

During your refresh phase, you may remove one focus token from each card you own; objectives, enhancements, units etc.

There is only one deployment phase, so units and enhancements play during that phase unless a specific card text allows them to deploy at another time. This phase is before engagements happen. 

You can choose to use cards in any order. If you play Yoda during turn A, and then play Luke turn B, you may strike with Luke and choose to not engage with Yoda, even though Yoda was deployed before Luke.

Did I hit all your questions?

I think so. Thanks.

I think someone needs to watch the tutorial videos and read the rulebook.