A 736

You can execute those maneuvers while wielding a reach weapon, but you probably wouldn't like the results. Adamantine Hurricane is explicit in applying only to adjacent creatures you threaten, so wielding a reach weapon and not threatening adjacent squares will simply waste that maneuver. Mithral Tornado requires you to make an attack against all adjacent opponents, so you would be forced to use unarmed strikes if you wielded only a reach weapon. That's the case even if you would provoke attacks of opportunity for every one of those unarmed strikes.

A 738 No.

An attack of opportunity is always a single melee attack into a square you threaten. Poison Spray is an area effect, not an attack, and also does not threaten.