I have ideas that would probably be filed under "illegal hardware modification", but meanwhile regarding cast-sequencing:

[code:1]
Macro Press 1 press 2 press 3 press 4 press 5
Sh1: trinket totem /p 4 next /p 5 next /p me next
Sh2: /p me next trinket totem /p 5 next /p 1 next
Sh3: /p 2 next /p me next trinket totem /p 1 next
Sh4: /p 2 next /p 3 next /p me next trinket totem
Sh5: totem /p 3 next /p 4 next /p me next trinket[/code:1]

Then you just need to do some LUA magic and make a mod that listens to and displays which shaman is next. Something which I'm researching for future multiboxing - I want to code addons and UIs for WAR once it's out.

(yes I messed up the X and Y variables! I blame the heat)