There are 6 optional collectibles in Episode 2: Rules. Each optional collectible will unlock a specific achievement / trophy. If you have completed the episode, you can go back to specific chapters in collectible mode and not affect your decisions in the episode.
Here are the timestamps for the collectibles:
0:34 - #1 Back In Time
1:42 - #2 Family Business
3:22 - #3 Bad Santa
4:14 - #4 Heirloom
5:11 - #5 Teenage Angst
6:14 - #6 Small Town Blues & A Private Journey
Here is a video guide with English commentary!
Here is a playlist of guides for this game!
https://www.youtube.com/playlist?list=PL-HeW6XkKdUJNaduS4UQz...