Those who use the runes can you wear any kind of armors except where noted: "You cannot equip Runes"?

For exemple: can an enchanter use the "Heavy leather armor" (copper treasure) or the "Chain mail" (shop item)?

Everyone can use all kinds of armor. But if its stated "You cannot equip Runes" you have to discard Runes into your backpack. As you assumed this is suboptimal for a mage who uses Runes, but he could use e.g staffs.