I agree that a bow wouldn't really be too different from the magic system, which is why I don't want to see it become a primary weapon. I enjoy the bow as a tool, like any other Legend of Zelda-esque tool item.
There's only so many different ways you can make mechanics for attacking at a range and I think between the magic system and Throw, the game has them all covered.
If the bow did get upgrades, I'd only want to see it in the form of Talents that unlock when you get the bow, not Skills. Talents require no additional animation. But even then, you only get a limited number of arrows. Why sink talents into something you can only use rarely? The alternative is infinite arrows which is ridiculously broken.
This is another big question that should be asked. There wasn't much already covered by the developers that the bow really could bring new to the table to justify a primary status.
I did point out a bow being a main use for flying enemies but I'm sure that development is being worked on to make some of the magic skills focus on that as I type.