CharactersDan has a tendency to develop a character over a course of several seasons, only to completely throw said development out the window for a cheap laugh, which often isn't that funny to begin with. Many characters suffer Flanderization as the series progresses.
ContinuityHe completely ignores it, Rule of Funny or even just lazy writing completely over-rules any idea of continuity. If there is continuity it's almost always an episode specifically written to be in continuity (like a sequel episode). Will completely Retcon a character to fit a single episode plot.
ShippingEven though he trolls his fandom, he will use the two main types of romantic storyline in his genre, first being the Just Friends style relationship, and the other being the Belligerent Sexual Tension style. Admittedly this can lead to confusing shipping agendas and fan wars.
FandomTrolling Creator — And how!
Running Gags/ThemesComedic Sociopathy. In spades.