1) A committed character is exhausted after it has been committed to a story. Then the other players commits to a different story. Can the first player still use the now exhausted characters?1) That's actually impossible. As the defending player, it's not allowed to commit characters to a story where there isn't a committed character from the active player.
2) Can a player commit a new character (from hand) when the opponent commits to a story (by paying the necessary resources)?
3) When a character is killed or goes insane, does he still count toward the other story checks (Arcane/investigation)?
4) My understanding is that at the last step of the Story Phase the players do a Skill check (sum of number on white background on committed cards). The "Detailed Turn Sequence" at the end of rulebook (page 13) does not mention it. Am I correct?
5) Other than the Resource attachment, which other action is optional ? (I believe that committing to a story is optional)
2) There are characters that can be put into play from your hand, but it will have to say so on the card.
3) No, because they're removed from the story right away. When the outcomes of the other story struggles are determined, they're no longer present.
5) IIRC, the only non-optional things in the game are:
- At the start of the game you must draw 8 cards and resource 3 of them.
- In your Draw phase you must draw 2 cards (1 for the starting player in the first round)
- If one or more of your characters are insane, you must restore one of them in your Refresh phase.
Everything else should be optional.