Something about how the ponies act in certain episodes...

This has been on my mind for a while. It's basically a way for me to explain why the ponies are behaving the way they are in certain episodes. I know I could just easily rewrite the ENTIRE series from scratch, but I think it's more fun to work with what we already have. It does add extra layers to these characters. So here's several examples that are canon in my AU:

• Bridle Gossip - Applejack and her family had a bad encounter with a zebra once. This resulted in her becoming superstitious about Zecora. As for her friends, she told them about the events at some point after the first episode, and they believed that zebras couldn't be trusted.
• Owl's Well That Ends Well - In the past, Twilight Sparkle was neglected and treated badly by some of her old friends (basically ponified versions of the Shadowbolts from EQG), and unfortunately, all this ended up rubbing off on her. Although, she has been seeking some help after the events of that episode.
• Luna Eclipsed and A Friend in Deed - Pinkie Pie has a habit of getting overexcited, which she is aware of and tries to control herself to make sure she doesn't go off the rails. Unfortunately, those two days where ones where she did indeed go off the rails.
• One Bad Apple - Babs Seed's attitude actually had nothing to do with her being bullied; she was just very nervous to meet her cousin, so she joined Diamond Tiara and Silver Spoon to get away from her. She also put on a bullying facade as well to keep her cousin further away.
• Wonderbolts Academy and future episodes with Spitfire in it - Spitfire was born with Multiple Personality Disorder. While she is actually very nice (like in the first 2 seasons), she switches to a tougher and more-military-like persona (her personality from Season 3 onwards) that gets triggered upon hearing a whistle. Rainbow Dash and the Wonderbolts are the only ones who know of her MPD, hence why they don't complain about being yelled at too much.
• Rainbow Falls - Spitfire and Fleetfoot were just very excited for the competition and weren't really thinking straight when they decided to have Rainbow Dash take over Soarin's spot.
• Somepony to Watch Over Me - Apple Bloom has been through many close calls lately, which resulted in Applejack being worried for her sister.

What do you all think? What headcanons do you have that explain why ponies act the way they do in certain episodes?