Continuity mistake: When Finn is going to an escape pod to run away, he puts his pack down in front of it, seen again in a later shot. When Rose realises he's trying to run away, his pack has moved itself inside the pod.
Continuity mistake: When Rey is following Luke up the hill in the infamous milk scene, her holster switches from being on her right side, to her left, and then back again.
Continuity mistake: As Poe Dameron starts his attack run against the Dreadnought we initially see him from the side and his helmet microphone is folded out to the left away from his face. The camera cuts to directly in front of Poe and the microphone is now folded in and directly in front of his mouth. (00:03:25)
Trivia: Mark Hamill's three children have cameos as Resistance fighters.
Continuity mistake: After the scene showing the First Order ships appearing behind the Resistance ships, when Poe Dameron says "It's Snoke's ship. You gotta be kidding me!", the immediate next shot shows him further away and facing a total different direction from Admiral Ackbar. (00:26:30)
Answer: As he says, "let the past die. Kill it, if you have to." Han was his past - he didn't hate his father, but his existence was holding Kylo Ren back from reaching his full potential, or so he believes. The principle is demonstrated earlier in the movie when he can't bring himself to kill Leia, but has no issue with the other TIE pilots blasting the bridge and (he thinks) killing her. He wants to free himself from the shackles of his parents, who cause him such internal conflict. Remove the source of the conflict and he believes he can move on to greater things. Of course, arguably his position is a bit naive, and his actions will actually cause him greater problems down the line.