Sooo . . . is Azir a Battle Mage or an Artillery Mage?
If he is supposed to be a battle mage, he shouldn't have that high amounts of high ranged ability poke. Like you wouldn't give Brand that kind of ability range, right?
At the same time, if he is supposed to be an artillery mage, he shouldnt be so safe and have this much defensive capabilities, with his Q-E and ultimate. Would you want a Xerath or a Ziggs to have that? Hell no.
Pick one and balancing him will be much easier. If you insist that he's both he'll either be sub-par or overpowered for the rest of his existence because this way he has no inherent weaknesses in his kit.