Absentee Actor: Sonny and Tawni were the only main characters to appear in every episode.
Nico was missing from 2 episodes: "Sonny: So Far" and "Sonny with a Grant"
Grady was missing from 1 episode: "Sonny: So Far"
Chad was missing from 3 episodes: "Sketchy Beginnings", "Cheater Girls" and "Marshall with a Chance"
Zora was missing from 19 episodes: "Three's Not Company", "Fast Friends", "The Heartbreak Kids", "Battle of the Networks' Stars", "Sonny in the Kitchen with Dinner", "Guess Who's Coming to Guest Star", "Hart to Hart", "Sonny: So Far", "Walk a Mile in My Pants", "Sonny Get Your Goat", "Sonny with a Song", "Random Acts of Disrespect", "Grady with a Chance of Sonny", "The Problem with Pauly", "That's So Sonny", "My Two Chads", "Sonny with a Kiss", "Sonny with a Grant" and "New Girl"
Chad's wall of banned has Zac Efron on it for reasons unknown. Fast forward to Starstruck, Christopher Wilde (Sterling Knight)'s girlfriend dumps him for Zac offscreen. Not to mention in 17 Again, where Zac plays Sterling Knight's dad.
Ho Yay: Nico and Grady, bordering on Ambiguously Gay. For example, one episode had Grady and Sonny pretending to date whilst Nico and Tawni pulled a prank. Later when they meet up they both ask "Was she better then me?" That's right Nico was asking if Sonny was a better girlfriend then him.
Tia: And welcome back to Tia. I'm here with Hollywood's it couple du jour. Sonny Munroe and Chad Dylan Cooper, or as I've just decided to call you, Channy. Sonny: Oh, that's cute! Channy, I like that. Chad: Oh, we've got our own mashup name.
However, the revamp is not temporary anymore. Demi won't be coming back anymore, although some of the cast members said she's welcome to come back anytime, or at least guest as herself, but it did not come to pass either as the spinoff only lasted for one season.
Replacement Scrappy: The Defictionalization of Mackenzie Falls led to the previous actors being dropped. The most noticeable of these is the ditzy Portlyn, Chad's onscreen love interest (who the fandom took to shipping with Nico). Her replacement Penelope didn't sit well with fans. Though above is another reason.
Shipping: Channy (Chad/Sonny) as the Fan-Preferred Couple by a huge margin. Next biggest is Tawni/Sonny. Occasionally other ships are teased, such as Sonny/Nico in the pilot (with no Chad), and Sonny/Grady in another.