That's the paranoid wizard inside me speaking I guess. Adamantine is nice for the hardness just in case it ever gets in the way of a sword or collapsing inn or something
True, too bad you can't have the Crossbow made out of Heavy Adamantine. Heavy is described as being made out of gold, and listed under special materials. So no go on that.
Source for the Initative quality? And the prices of the following would be nice (my Draconomicon is at the house):
Gorget of Tempest Breath
Draughts of Metabreath Magic (specific ones)
(Greater) Pectoral of Maneuverability
That should be it, aside from the wands, staves, and scrolls.