Well just got off of work and WoW is still down for maintance On the bright side, gives me time to write this up.

As mentioned above I am using the FTL setup. I am also running all 5 on 1 pc, and using Windows Vista 32bit.

On Keyclone Hotstrings, I have my Starfire spell bound to 'R' for the "main toon" and the macro bound to "=" for the slaves. I have set up the hotstrings for my Starfire spell the same as my Wrath and Moonfire spells (changing the last key of course).
I have checked and rechecked each toons keymap file and they all are in this way, so I, as far as I can tell, have not entered anything incorrectly.
Also to note, I currently have my follow, wrath, and moonfire spells working correctly. It's just the starfire spell that has me confused.

Toon A
# ALT (when this one is main - all slaves cast starfire)

Toon B
# CTRL+ALT (when this one is main - only Toon-C casts starfire w/ her)

Toon C
# ALT+SHIFT (when this one is main - all slaves cast starfire)

Toon D
# CTRL+SHIFT (when this one is main - only Toons B & C cast starfire w/ her)

Toon E
# CTRL (when this one is main - only Toons B & C cast starfire w/ her)

For Toon-A
R --> SFI-A
CTRL+ALT+= --> SFI-B
ALT+SHIFT+= --> SFI-C
CTRL+SHIFT+= --> SFI-D
CTRL+= --> SFI-E

For Toon-B
ALT+= --> SFI-A
R --> SFI-B
ALT+SHIFT+= --> SFI-C
CTRL+SHIFT+= --> SFI-D
CTRL+= --> SFI-E

For Toon-C
ALT+= --> SFI-A
CTRL+ALT+= --> SFI-B
R --> SFI-C
CTRL+SHIFT+= --> SFI-D
CTRL+= --> SFI-E

For Toon-D
ALT+= --> SFI-A
CTRL+ALT+= --> SFI-B
ALT+SHIFT+= --> SFI-C
R --> SFI-D
CTRL+= --> SFI-E

For Toon-E
ALT+= --> SFI-A
CTRL+ALT+= --> SFI-B
ALT+SHIFT+= --> SFI-C
CTRL+SHIFT+= --> SFI-D
R --> SFI-E

My Macro, I use the /click command to call the targeting macro, then cast the spell.

Targeting Macro
#TARGET(MultiBarLeftButton12)
/target [nomod:ctrl,nomod:shift,mod:alt,target=Sotkia][mod:ctrl,mod:alt,nomod:shift,target=Kawnie][mod:alt,mod:shift,nomod:ctrl,target=Jaeni][mod:ctrl,nomod:alt,mod:shift,target=Rauma][mod:ctrl,nomod:alt,nomod:shift,target=Lurie]

Spell Macro (bound to = key in WoW)
#STARFIRE
/click MultiBarLeftButton12
/cast [target=targettarget,harm] Starfire