Mathematicians. People who need to know nothing and make up stuff and yet make us believe they practice the purest form of science. Link. The economist in me respects that.
I think FlutterGilda is worse. Blueblood is an uncaring jerk, but he doesn't try to actively hurt people.
Huh, I thought I was the only person in the internet who doesn't care for that show.
Pffff. If the "worst" in your family is an unknown half-sister I'd consider it in the range of "dull and boring". People make mistakes and reconsider things and change. Every family has it's stories and secrets.
Some other suggestions:
Soarin is more competent in some fields and has more experience. He has seen a lot of Equestria while touring with the Wonderbolts. He lives in the court near the centre of power. Also he had probably a very good education since he is from a noble family. His parents might have called some favours to get him in a good school. He might have gotten further education at the Wonderbolts, maybe even an university degree. (In modern German military it is expected for officers to have one, and for non-commissioned officers to have an certified training/apprenticeship, although physically demanding fields are the exception). I don't think he is smarter than Big Mac and I don't think the formal education was his thing. But he was in contact with a of different ponies and their ideas and that's a pretty decent catalyst for gaining knowledge.
Or maybe Applebloom underestimated Big Mac because she is close to him while she's impressed with Soarin's rank and title. People and probably ponies alike tend to be blended by fancy new things.
Or she doesn't want to bother Big mac because he has a lot of work to do, while Soarin as guest has to do nothing and is eager to help.
I didn't expect this to say: I liked it. Applejack does have the greatest accent ever. They really had a ingenious idea with that.