I am pretty new to this whole thing but have started battling with some friends for fun recently. I normally play as empire, so my friend chooses rebels frequently. The other day, he used Poe and used his ability. He said, because of the way the card reads, that he can change a focus to a hit, even when he is defending. Is this possible? I thought he could only modify the dice but he argued against it.

Next question! I love to use Youngster for our larger battles, I was wondering if his ability is limited to only Elite upgrade cards with the phrase "Action" on them? Or is it possible for me to have him use Ruthlessness or something of the like with his ability?

I'm not sure what your question is about Poe but Poe can change one of his focus results to a hit or evade when attacking or defending.

You are correct about Youngster. The EPT must have the ACTION header.

Poe Dameron's card text says: "While attacking or defending, if you have a focus token, you may change 1 of your "eyeball" results to a "hit" or "evade" result."

So... if he is attacking, with red dice and a focus token, he can change a "focus" result to a "hit" without spending the focus token.

When he is defending, with green dice and a focus token, he can change a "focus" result to an "evade" without spending the focus token.

For your specific question, is it possible to change a focus to a hit result? No, as there are no "hit" icons on the dice he is modifying, he cannot modify to a "hit" result. The key word phrase here is "you may change 1 of your"... your dice... not your opponents.