These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: Mordecai Heller, the Obsessive-Compulsivehitman. His OCD arguably makes him even more of a monster - he once killed his getaway driver for sneezing too much. He launched into a terrifying tirade against a man he was going to kill because his position in the backseat upset the symmetrical balance of the car. Mitzi mentions that, when the Marigold gang gave him a better job offer than the one he had, he kneecapped Viktor, his partner of several years, on his way out the door.Perhaps worst of all, certain lines of dialogue indicate that he may have had a hand in the death of Atlas May, his previous boss and Mitzi's husband.Word of God has actually stated that Mordecai has no morals whatsoever.
Crack Pairing: From the Lackadaisy Shipping War! thread, we have Moron. Mordecai and his iron.
In the same thread, Pancky (Rocky/pancakes) was mentioned, however, the current task at hand is taking down all Domzi (Dom/Mitzi) shippers.
Serafine Savoy is a pretty good candidate for this.
Fan-Preferred Couple: Zib/Mitzi, otherwise known as "Zibzi". Tracy's confirmed that Zib and Mitzi were together in the past, which helps, despite her and Wick's current mutual interest.
There's also a good number of fans who prefer Viktor/Ivy to the canon Calvin/Ivy.
Fanon: Some fan dubs give Mordecai a British accent despite the fact that he's a second-generation Jew from New York City who gives Yiddish holiday greetings, probably because of Evil Brit and related classy Brit tropes. (Word of God says that he doesn't have much of any accent, having deliberately killed his New York speech patterns... with ice pick, probably)
Foe Yay: Serafine and Mordecai, according to some.
Fridge Horror: The events taking place in the comic start in 1927. Most of the characters are in their 20s or 30s, meaning if they don't get killed due to their profession, they get to have some fun during The Great Depression. This is hinted at in a doodle of Wick with the caption "October 1929".
Ship-to-Ship Combat: A minor example...the "shipping war," for example, was basically created for a random battle thread in the forums (and the leading contender was Moron). There is the occasional spat between the assorted Mitzi and Ivy pairings, but it's usually all in good spirit, since Tracy's following is very devoted to her and to the story at large.
Tear Jerker: Mitzi refused to sell the pearl necklace that her late husband gave her, because it's all she has left of him. Needless to say it is promptly broken as she desperately scrambles across the street trying to save it.
And let's not forget about Zib, who realizes than Mitzi is no longer the young, sweet and innocent Mary Ellen he used to know back in the days.
And in Lackadaisy Haymaker, there's just something upsetting about the sight of Rocky with a massive gash in his head. For a character so prone to Amusing Injuries, seeing him take a blow played so deadly straight is pretty damn sad.
Rocky's aunt pointing out that just because Freckle is the only person in the world who still trusts him isn't a good reason for Rocky to abuse that trust. She even suceeds in wiping the smirk off Rocky's face for a split second.
Viktor's had his fair share of bad luck in the comic and even before. What with the kneecapping and the shotgun wound. Ivy's also not particularly happy with him right now,which doesn't help Viktor much.