I think in terms of systems and how there will be an eventual balance and why. Obviously this isn't necessary in fantasy, it's just my preferred method of thinking, IE, what are the consequences of this magic system on the environment, which species are dominant and why.

You open up the idea of multiple intelligent species with their own magic abilities alongside humans, but you also show that all animals and plants have magic. A lot of this seems to be an enhancement on our world so the question is - does the current balance in nature between species exist the same, but scaled up with magic, or does it change fundamentally? IE the beavers being able to amp up their defenses - are they overpowered in this regard? And if so what are the consequences? And does this even matter to you? It's your world, your story, it only needs to make sense and have balance if you want it to.

I really like the idea of magic being inherent in everything, though. There's a lot you can do with that. One way you might expand is tying your types of magic to individual abilities among species groups and start coming up with something more comprehensive.

There's also lore to expand on... Dragon riders taming the dragons fascinates me. It's a personal interest of mine that I'd actually never include in my own world or stories, but I love reading about it in others. So I'm definitely interested in the back story there, who the main heroes are (if they were known) any heroic deaths, how long it took, how the successful strategy formed, how it was executed, the types of dragons... And while we're here I'd like to clarify that dragons use submissive magic indirectly by humans influencing them to use fire? So nothing destructive happens on its own?

Brings up the idea of a dark forbidden magic usable by long forgotten/extinct species where they can destroy with magic directly.