Yeah the whole thing is a clusterfuck.
I could easily write something better off the top of my head.
Instead of trick or treating, Sue is hosting a Halloween party or has heard about one nearby. Jordan is going and Sue begs Lucy to come, but it's costume only. Lucy gets the same schtick to be careful and decides to ask Augustus to champerone (same as in current comic).
They show up at the house party, we see most characters from High School there. Sue is insistant they have a good time while Lucy and Gus are annoyed by the semi-drunk attendees. Mike is there via Paulo and David who keep trying to loosen him up - he doesn't want to until he see's Lucy. Mike begins to drink to excess.
Same kind of drama happens when the two meet, Mike is more belligerent when drunk and the others are holding their alcohol to various degrees. The outbursts against Paulo and Daisy make more sense.
Lucy gets triggered and goes away to drink and/or share a joint with Augustus, she lements to him about how she is to blame for Mike being an ass. The two makeout and Mike could walk upon this. He gets upset runs out to call Sandy and leave drunken messages but to his surprise she actually picks up..
Sandy breaks up, Mike runs out vomitting in shock/drunkeness and stumbles home.
There, it's at least more age-appropriate for 15-18 year olds then the current story, which treats them about 10-12 years old.