Thanks for your interest~! Now, on to answer some questions:

[@Wanderer of Philosophy] In theory, what you've described is possible, but ultimately it would be pointless. Whether you're using Mana itself or casting a spell (the two cannot happen together, as the existence of Mana itself destroys a spells composition) the two would cancel each other out. Not to mention that Mana has to be pulled from an outside source, and large quantities of Mana rarely exist in a single place.

There is a very, very, very rare case of people being born that are somehow able to produce Mana from their bodies, however those cases die in infancy, at most they live until five years old. Further details are a plot point, so I will stop here, if you don't mind :)

[@Zeroth] In terms of movement, I was thinking more Avatar but with less martial arts - think basketball or tennis motions. On staffs and wands; those are tools that exist to simplify movement and facilitate an easier transition of energy to the outside. The downside, however, is that wands and staves cannot be used to exhibit more complex spells, which require require a wider range of movement.