*It seems significant that Ilana puts some of the ashes (from Jacob’s place of death) into a pouch.
*The kid tells BadLocke “you can’t kill him” because “it’s against the rules.” The earlier focus on children might be important here--the Peter Pan allusions along with the abduction of children. This young boy is probably somebody we already know—who is now an adult.
*BadLocke says, “Don’t tell me what I can’t do.” This was often spoken by Locke.
*BadLocke says, "What I am is trapped. And I've been trapped for so long that I don't even remember what it feels like to be free. Maybe you can understand that. But before I was trapped I was a man, James, just like you." This makes me imagine BadLocke and Richard imprisoned together—since he referred to Richard being in chains.
*BadLocke takes the white rock from the scale, leaving the black rock there and says, “It’s an inside joke.” This imagery reaches back through all six seasons, back to the very first episode—Locke playing backgammon with Walt.
*I think the title of this episode is important on more than one level. Obviously it refers to Locke as the substitute teacher at the end. But Sawyer is also apparently a potential “substitute,” along with all the other remaining uncrossed names.
*The flash-sideways is not an accurate portrayal of them not crash landing—Ben Linus is a teacher of European history. This is more than a hypothetical "what-if."
*The big reveal of the numbers is definitely significant. 4—Locke, 8—Reyes, 15—Ford, 16—Jarah, 23—Shepherd and 42—Kwan. Locke’s name is now crossed off. If "Kwan" is referring to Jin, then all the names are male.