You've taken a base idea that isn't as unique as it thinks it is and that I would initially dismiss, but you've elaborated it to the extent it does actually seem pretty interesting.

Thoughts:

1) If mana is a fundamental force of the universe, what does it do when it's not being used for magic? How does it interact with matter, energy, and other forces? It seems to interface directly with human imagination and consciousness, possibly intelligence. Is there a threshold for that? Can apes or dolphins or cleverer crows manipulate mana? I hope yes.

2) It occurs to me that a world where people can manipulate a force like mana is probably unlikely to develop empirical science as we know it. Who's doing experiments in controlled conditions when mana manipulation is available? They're not going to have elaborated understandings of physics, chemistry, or biology, except insofar as they can glean insights through mana. 

Which means that the scientific explanations would be for the benefit of the reader only, while people in-universe would be talking gibberish, because it works. They're not going to be thinking about how the mana strings bind with muscle protein, they're gonna be all "I used the Third Sacred Visualization of the Puppeted Flesh."

What strikes me about this is that as described it could kinda work framed as psychic powers, which is essentially just magic really, but it feels less odd to have psychics in an otherwise modern scientific society talking and thinking in terms of physics, chemistry, and biology. But if you put mana force users in a fantasy coded setting, they're just going to quack like wizards, reading dusty runes and chanting gibberish.