I know I'm gonna get a lot of hate for this but, I absolutely HATE the way the writers handled the way magic is portrayed! Hell, even flight for Pegasi. It's almost as if the creators are handicapping ponies who aren't lucky enough to be part of the Mane 6 and have all the extra abilities. If you're a Unicorn and you have the ability to perform magic, you should have the ability and the potential to perform any kind of magic you desire if you study and train hard, like Twilight. But, you're telling me that since their Cutie Mark literally dictates their life, they can't become a strong magic user?
Bull... Shit!
If you have the ability to perform magic you should, like most other people would think, have the ability to augment and expand your arsenal of magical abilities. If you can't do that, what exactly is the point of being a unicorn?
The same goes with the Pegasi. Even though Rainbow Dash's Cutie Mark represents speed (I Think) why does it seem that she's the only one that can actually fly fast and create sonic booms? One would think that other Pegasi could do this same thing if they train enough, but the writers seem to be hell bent on handicapping every pony who isn't a part of the Mane 6, as I said earlier.
I really REALLY hate the a lot of the concept that gravitates around Cutie Marks. Just because your special talent is a certain thing DOESN'T MEAN YOU CAN'T DO ANYTHING ELSE!!!
Just take Rarity for example!
Ya see, this is why I usually don't like Cannon when it comes to things like this. It's stupid. A Cutie Mark shouldn't dictate a pony's life and effectively put limits on it. They should be able to practice, study, and execute whatever maneuvers they damn well please.
Now, if you'll excuse me, I'm gonna go eat some Shrooms.