I meant for the Druid to use. As it is, the Druid can only use Leather Shirt and Hide Mail.
Yes, this is by design. We want the druid to be different from the cleric.
And don't you mean, "Hide Armor", or "Hide and Mail"? And "Scale Armor"? Mail doesn't mean 'armor', mail means 'chainmail'.
Mail means any armour set made with rings. But the actual name doesn't matter. The idea is to use the name 'shirt' for all light armour, 'mail' for all medium armour and 'plate' for all heavy armour. I think that simplifies things.
Will there be magical Chain Shirt types with no reflex penalty and no spell failure chance, for the wizard to use? IE, stuff that you are automatically proficient in it, and can use it alright, no matter what?
As a general rule, no. As a special item (artifact), yes why not. For wizards, there will be bracers of armour and (probably) magic robes.