Ok I have a player that always uses the spell Clairvoyance to search areas she herself has not been in, such as a wharehouse with no windows. The discription seems to allow the caster to send this point of view anywhere not blocked by a ward. Is this right?

Of course, if it's not warded, then that same magician can always just use astral projection and run inside and check things out.

If the warehouse has a magician keeping an eye out for that sort of thing, well, then he's just as likely to see the Clairvoyance spell go off in astral space as he is to see the guy's astral form come walking in through one of the walls.

Either way, the spell doesn't really add anything that unbalancing to the game. Remember, the magician's cyber-filled buddy can always get a radar implant and see through walls, too.