Some of the domain powers are listed as Supernatural, which means that they take a Standard Action to turn on and to turn off. This is not in keeping with some of the powers that are scaled for 1 round/CL.
I would suggest that there be a notation that these are activated as a Swift Action, and last for one round, usable a total of 1 round/CL each day.
Examples:
Walk on Air (Air Domain)
Animal Form (Animal)
Chaos Blade (Chaos)
Body of Stone (Earth)
Scythe of Evil (Evil)
Crown of Flames (Fire)
Holy Lance (Good)
Staff of Order (Law)
Bramble Armor (Plant)
Might of the Gods (Strength)
Flight (Travel)
Weapon Master (War)(almost useless as written)
Mantle of Ice (Water)
I have not looked over the arcane schools or sorcerer bloodlines at length, so there may be similar effects that should also be on this list.
-Scott