All Dragon Armor Locations (and bonuses)
For the dragon form I removed all equipment except for the Bone Dragon Cuirass (+40% hit points) and Bone Dragon Leggings (+40% offense) once I could max Firebreath, Fire Sphere, Dragon Spirit and Dragon Burst without the need for equipment spell bonuses. I didn't use Dragon Burst that much (came in handy a couple times), and never tried the summon, shield or polymorph spells.
AFAIK there are no extra bonuses for wearing all one style of dragon equipment.
It isn't really surprising that, in a land of magic, weapons would be forged that could do magical damage, for use by those intelligent enough to focus/control the effect, but not necessarily well trained in using magic directly. Practically you could argue there is too much overlap between magic spells and magic based bows, or the design of the damage / resistance / combat system should have been different, but at least in principle magic bows of some form would be expected.
