As with every previous season, Weiner was tight-lipped about plot details in the flood of publicity that attended the show’s return in March, even going so far as directing critics not to spoil viewers’ fun by revealing key story lines. But while taking a break from his feature directorial debut, “You Are Here,” Weiner talked about the narrative choices centered on office politics, marriage, personal pain, sex and race for this season’s show, which is enjoying some of its best ratings ever.