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.
Cry for the Devil: The Flim-Flam brothers are jerks, yes, but it's hard not to feel sorry for Flam when they get separated during the sandstorm in the San Palomino and he thinks Flim might be dead.
Harsher in Hindsight: Soarin's eating habits making him fat was a funny and subtle gag in Windfall. Then chapter 4 of this story comes along, and Soarin is now so out of shape he gets kicked off the Wonderbolts.
Applejack's comment to Soarin' about his mother not teaching him any manners become this when you take his family situation into consideration. She realizes this in chapter 10 and immediately apologies.
Squick: Chrysalis offering to make love to Blueblood while disguised as Rarity, something he actually considers.
What an Idiot: Flam/Professor Destiny's first attempt at "sabotaging" the flight harness is to fire a magic-seeking rocket at it. Then he, while still standing next to it mind you, uses magic to lift a spyglass to watch the results. Naturally he goes boom.