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.
Dude, Not Funny!: The ending to the second film; Dale gets shot by Rex while the former attempts to stop the latter from shooting a policeman and for essentially ruining his life, Motherfucker Jones steals all the money, Julia raped Dale in his sleep, and it is heavily implied that Dale's wife is sleeping with Julia (Julia even flat-out says she's going to fuck her). While they keep the business, the ending is much more tragic for Dale than happy.
Flanderization: Dale and Kurt get significantly dumber in the second film.
Julia is far more of a depraved sex maniac in the sequel. She's an admitted sex addict (whom therapy is lost on), a scat fetishist, and a pedophile. She also plans to bed Dale's wife.
Fridge Horror: As stated above, we find out in the sequel that Julia is sexually attracted to 14 year old boys. Considering that she's not above taking advantage of patients after gassing them, God only knows how many underage patients she's molested in the past.
Idiot Plot: Recording their conversations with their bosses right from the start would have solved a lot of the main characters' problems to varying degrees, but it takes them the entirety of the movie and a tip from a petty gangster wanna-be to figure that out. When they try it the normal way they're thwarted by their own constantly increasing stupidity.
The ironic thing is the recording actually would have worked, but Kurt choose to bail on the job to have sex with Harken's wife.
And two of them already had ample evidence to convict their bosses as it is. Julia had recorded evidence of herself molesting someone under anaesthetic, and Bobby wasn't exactly being discreet about his cocaine use.
In the sequel, the gang is rather astonishingly quick to jump to criminal actions after what happened in the first film was the result of years of pent-up rage.
Bobby crosses it so many times in his first scene as Kurt's boss.
Julia almost crosses it when she threatens to lie and tell his fiancee that he's a (false) sex offender and finally crosses it in the sequel when she rapes Dale while he's in a coma.
Rex crosses it in the sequel when he kills his father.
Bert crosses it when he calls the police even after the trio threatens to kill Rex if he does, confirming that he loves money more than his own son.
Nightmare Fuel: Harken's murder of Bobby. It's the only scene in the movie that's not Played for Laughs, and it's surprisingly realistic. Not unexpected if you've been paying attention in the coming seconds, but still a bit of a shock when it comes.