Headcanon: Pony Magic and Abilities

It is my general observation that there is a uniqueness to many ponies besides just the obvious that comes with a cutie mark. Magic fuels every aspect that makes the pony special, the cutie mark being just the most prominent clue placed on the main one. First is that if a pony is lacking in abilities pertaining to their tribe, it will be compensated for not only with what their cutie mark is telling them, but in other ways. The primary example is of course Fluttershy. She has only the bare minimum ability of a pegasus without being a chicken (Sorry Scoots) and in exchange not only does she demonstrate earth pony magic, but also has her stare, something I speculate is a powerful applied version of animal care magic that is usually only used innately by earth ponies.
In contrast to this innate compensation is the applied version: Bulk Biceps developed all his muscles, but he had to have especially trained his wing related muscles to lift himself with Scootaloo wings. (Of course his and really all pegasi flight still violates known laws of physics, but that's a topic for another post.) Even a few hours of sufficient training can show significant improvement in flight as shown by Fluttershy, though hard work leads to improvement isn't a unique observation. So what about the ponies talented in the tribe's abilities?
Rainbow Dash is without a doubt loaded with pegasus magic like Naruto with chakra. While other cutie marks appear with an epiphany or simple fate, she made hers appear being drawing out so much of her magic at once a cutie mark had to form just to manage some of it. I speculate the sonic rainboom and the trails left behind by Wonderbolts or other talented pegasi are excess pegasus magic being released into the atmosphere, possibly even as part the natural magic cycle of their world analogous to the water cycle they're missing.
Speaking of, the correlation between the cutie mark and the maturation of the ability to manage innate magic is a cornerstone to this headcanon, Foals a month old manifest abilities they won't control again for years possibly because innate magic is something conserved automatically a little later on in preparation for gaining a cutie mark. It's even possible that under normal circumstances, the less innate your talent is, the less controllable just before the cutie mark is about to form, explaining Rarity's magic controlling her, Twilight's not working one moment, than manifesting at full power the next, and most importantly, Rainbow's excess magic releasing even harder than it does under normal circumstances as a grown mare.
This leads us the concept of an earth pony that can absorb non-innate magic, which they do not have the means to vent out when in excess. I refer to Pinkie Pie, who after being practically bathed in excess pegasus magic which inflated her mane and tail, gained a cutie mark in the opposite of her life experience and abilities that would confound a unicorn. She's not lacking in her own tribe's magic like Fluttershy, so she just has more magic than an earth pony is supposed to. I'm going into full random headcanon territory when I compare this to kekkei genkai from Naruto, having two natures that combine into a new nature, best summed up as party pony magic. (Alicorn magic thus being like kekkei touta follows but I'm getting lost in the analogy.) Interbreeding among the three tribes made such a thing inevitable. Maybe Cheese Sandwich has some pegasus genes that makes him an equal practitioner of party pony magic.
Some final speculation; another explanation for the sudden burst of magic from Twilight might be that she too absorbed the sonic rainboom's excess magic, then immediately vented it out in the form of those various spells. This experience of pegasus magic flowing through her might have been the catalyst not just for her cutie mark, but for her potential to have wings of her own.