- The first word in the shout can do 50 damage every 30 seconds. That's 1.67 DPS.
- The second word in the shout can do 70 damage every 50 seconds, for a result of 1.4 DPS.
- Lastly, all three words does 90 damage every 100 seconds, for 0.9 DPS.
Here's a really hilarious one:
Whirlwind Sprint
- First word moves 50 feet every 20 seconds, for 2.5 FPS.
- Two words moves 75 feet every 25 seconds, for 3.0 FPS.
- Finally, 3 words moves 100 feet every 35 seconds, for 2.86 FPS.
I'm not saying anything extreme, I'm just saying that this current cooldown system seems inconsistent with itself, and with http://www.gamesas.com/topic/1366766-your-thuum-is-truly-powerful/page__fromsearch__1.
For these reasons and the reasons in the above link, I really do think that a single, static cooldown is what would make the most sense for shouts. All shouts, all levels, everything should have the same cooldown. Say, 30 seconds.
From that point, you balance the damage output and duration of the shout around that. If you want a stronger shout, do slightly more damage. If a shout is too powerful, such as Storm Call, then make it last longer/shorter duration, and do more/less damage.