Magic missile always hits and is reliable. Thanks to an item found in the underdark, it becomes OP. Wizards can already learn any spell, which makes Cleric obsolete in my opinion. My mage can use Inflict wounds as low range burst damage. If I remember correctly, my Wizard can even learn bless. And guiding bolt can be learned aswell.
At this point Wizard does the things a cleric does way better, because Wizards have more spellslots.
Headband of Intellect is OP. Its so OP that players are going to metagame and dump Intelligence while gaining 18 int for free just because of this item. It is too powerful, should be reduced to 16 int, which is what you can get with level 4.
In general, magic items like the Circlet of Scorching or the Hag staff both use intelligence as the stat which governs your chance to hit. That means, your Wizard gets a free cast of Scorching Ray every long rest. Or infinite casts of the poison attack (but deals poison damage to yourself).
However, these items also use intelligence as casting stat if you are not a Wizard! Wizards don't need a free cast of scorching rays, but Warlocks do since they only get to cast 2 spells per fight. But the way these magic items use intelligence as your stat, you are going to have a terrible chance to hit with your free spells from these items.
This needs to be changes ASAP. Magic items which grant free spell casts per rest must use your casters' casting attribute like Charisma for Warlocks. In the current situation, these items are better for Wizards than they are for other casters, and Wizards can already learn any spell.
This is just ridicolous and makes Wizards the best casters in the game. Warlocks, Clerics and eventually Sorcerers can't compare with them at all and they are even disadvantaged because items use intelligence for casting. Please adjust this to give other non-Wizard classes the same hitchance with those spells granted by magic items.