Board Thread:Questions and Answers/@comment-27573562-20160422081100/@comment-5956954-20160422081728

1 and 3: Read this.

Number 2: Read this.

Short

It is impossible to fight Sans before Papyrus, Post-Genocide affects the True Pacifist Ending since you sold your SOUL, the Hangout is when you decide not to Flirt with Papyrus, and he will interpret everything you say as something positive, so hating everything is just as nice as being nice.