I believe 45 seconds pause is a bit too long for the purpose of discouraging flooding. 30 seconds is more appropriate and will be as effective.
Come to Pakistan…this flood control is no flood control actually! 
How about 25 seconds? Would that discourage flooders slightly less, or perhaps make no difference in the overall scheme of things?
My caculations say 31.6768 seconds. How did you get your figure?
25 seconds sounds about right. It will discourage flooders and encourage geniuses like myself who type very fast.