the gun is for the hitman that shows up in the garage,
Just anna herself has several endings even one from the very start if you deny the StarMaker idea, plus running away from the family (good and bad depending on relationship status) , stopping starmaker when youve paid the debt off and a happy family ending.
plus the ones for the other characters, ill try another playthrough though but i think i got about 8
also want to know the answers for 4,5,6