Magic worldbuilding system for a Digimon fantasy AU

Hi everyone. I hope no one's sick of me yet. I have a magic system I started creating for a Digimon fantasy universe, but I'd like to hear other peoples' thoughts and opinions on it and what I should add.

1.Magic is Inherent or Learned — all magical ability is genetic. ‘Ordinary’ folk inherited the ‘gift’ from powerful sorcerers (or were they gods?) from other worlds who decided to visit and left some genetic heritage behind. In fact, almost everyone in my main world carries some of the heritage of one wizard who visited way back at the dawn of their civilization (when the population was small) and decided to stay on for a few thousand years.

2.Magic is Common or Rare — fairly rare, but not so rare that people aren’t familiar with it. In keeping with the inherited aspect, more individuals with abilities live in certain areas than others.

3.Magic is Secret or Public — public, in the stories I have crafted so far, but I could see that being different in other times. Sorcerers openly serve rulers, and magic and religion overlap. Those individuals whose gifts tend toward prophecy sometimes serve at religious shrines.

4.Magic is learned in School or in Apprenticeships or Alone — all, to some degree, but as an apprentice most commonly. However, those without a teacher may be driven to madness trying to deal with what they do not understand.

5.Magic is based on Memorizing Spells or Willpower and Higher Understanding — Spells (and ‘magical’ items) serve only to focus the practitioner’s mind. As magic is essentially the ability to see into and partially enter other worlds, it requires knowledge primarily but also a certain amount of will. Incidentally, the gift is not homogeneous among the sorcerers, who vary considerably in ability.

6.Magic has a Price or is Free — not a price, per se, but as with physics, any action has a reaction. A wizard must take this into consideration and know what side effects may accompany his magic. As mentioned above, there is also the occasional price of being driven mad by ones gifts, of not being able to shut out all the other worlds one can sense.

7.Magic is Limitless or Limited — in that it is an individual ability, it is limited by that individual’s own strength and intelligence. But the potential is unlimited — as infinite as Being.

 

The story is called Blood Legacy. A large number of people have the ability to use magic, having been born with it after it manifested as superpowers.

"Can there be magic pollution in an area due to overuse?" I think I'd describe my answer as: rippling energy that remained stagnant in the air; it was only a small amount at first, but if left alone, it would wreck the ozone layer in time.

"Reality warping?" Can I just say I love your ideas, mate? They're brilliant. The very fabric of reality warping from too much magic in the air sounds awesome.

"Castings that are beyond the user's ability to control that result in Chernobyl-type incidents?" Hopefully, there won't be any of that, but it is a cause for concern should an inexperienced magic user get in over their head.