Nidalee should get punished if she misses her spear.
Basically, the base cooldown of the spear should be increased by "X" amount. Then if she misses the spear, it will start from that cooldown after the spear has gone through its full range. If she lands the spear, the cooldown should be reduced significantly by "X%" or "X amount, essentially rewarding her for landing the spear, and punishing her for missing. That I think should make it fair for people trying to dodge her spears every 4-5 seconds. Also one side note, the invisible spears are really becoming a problem.