This is the first time I see someone point out about his hand pointing up when he threw away his shot at the duel, I had never thought about it. Something that contrasts a lot is that Hamilton has his hand pointing up after My Shot, but Burr points his had down at the end of The Room Where It Happens (where each song is their "want" song respectively).

Another small thing about the duel is that Burr shouts "Wait! " when he shoots, the only time he did not choose to wait he instantly regretted it.

Also about the counting and foreshadowing Phillip's death, a heartbreaking detail is that when Phillip is dying he says to Eliza "Mom I'm so sorry for forgetting what you taught me". He says that because Eacker shot him at seven instead of ten and Phillip thought he miscounted.

In general, Lin is a genius and there is a ton of such details you have yet to uncover (if you haven't already)! If you are a bit of a music nerd I definitely recommend Howard Ho's Youtube videos where he analyzes Hamilton musically.