You have an asterisk next to "Who hit Harry's car?"  I'd like to know what the consensus is on that.

Consequences of Molly being taken to Arctis Tor: Harry went to Arctis Tor, as did Charity, Murphy, and Thomas.
Consequences of Harry going to Arctis Tor: Harry discovered Hellfire was used in an attack.  Harry discovered Slate was still alive.  Harry discovered Lea was encased in ice and being cured of madness through exquisite torment.  Harry ended Scarecrow.  Summer Fire met Winter's wellspring.  A bunch of fetches got killed.  Some snow ogres got killed.
Consequences of Harry discovering Hellfire was used to attack Arctis Tor: Nicodemus learned that Hellfire was used to assault Arctis Tor.
I have the feeling that this is way more important to Mab than Harry sucker-punching a fetch, no matter how badass it is.  Also, I disagree with the theory that Scarecrow had outsider stuff going on.  Harry's fire was stopping after a couple feet of travel, not immediately before hitting Scarecrow.  That's Winter choking it out until Summer countered it.