There should be a spell cooloff time in addition to the casting time so you can play around with spells that might be too powerful to have a slow casting time but not useful with a long casting time. Touch spells especially would benefit from this, because they could have a very low casting time, but a larger cooloff time. This would make them usefull but not overpowerful.
This suggestion is also posted on the bugtracker here:
http://planeshift.oodlz.com/bugtracker/bug.php?op=show&bugid=843&pos=0
