Must.... Stop.... Tweaking.... Macros!

Code:
#showtooltip Chain Lightning
/target focustarget
/stopmacro [noexists][noharm][dead]
/console Sound_EnableSFX 0
/use [mod]13
/cast [mod,combat]Elemental Mastery
/cast [mod,combat]Nature's Swiftness
/console Sound_EnableSFX 1
/cast Chain Lightning
In combination with the ? icon, this will display the correct tooltip. It will also turn off the annoying sound effects when your trinket is on cooldown. Add the ErrorMonster addon and you'll be rid of the "Ability is not ready yet" spam as well.