Quote 4
"Maybe they gave up and they're planning to leave us alone." (13.253)
This is Ender’s (correct) guess about the buggers. This hints at Ender’s big wish in his wars: that people would just leave him alone. For instance, he fantasizes about Peter leaving him alone (1.16) and he cries out to Dink that he didn’t want to attack Bonzo and wished that people would just leave him alone (12.122). What’s curious here is that Ender’s personal enemies simply won’t do that, but the buggers really are leaving humans alone.
Quote 5
"They don't want to teach me everything," Ender said. "I wanted to learn what it was like to have a friend."
Alai nodded soberly. "Always my friend, always the best of my friends," he said. (7.55-56)
Going along with our last quote, we can see that Ender’s friendships are still complicated: Graff may be his friend (in some way), yet he can’t, you know, go out and see a movie with him. Meanwhile, Alai may be Ender’s friend for ever, but they’re still separated here. So even when Ender has friends, those friendships are complicated.
Quote 6
"It's good to know I have a friend here." But Ender wasn't sure Dink was his friend anymore. Neither was Dink. (11.81)
Ender has basically this same moment with Dink, with Alai (10.175), and with Petra (11.104). In all these cases, Ender’s old friendship is damaged by the game and Battle School. This reminds us of how Ender’s friendships are complicated – by which we mean that Ender feels like he doesn’t have any friends. That's a bummer, no matter how smart Ender is. Now, all these kids do show up at Command School and Ender seems happy to see them. But since he lost these friends once, couldn't he could lose them again?