I don't think Red Mage (or Fencer) should get water nukes. Red Mage's primary damage should be from their sword and I think Water spells should be saved for a job that doesn't have another means of doing damage (like Arcanist).

Besides, just look at the spells Red Mage would have access to through CNJ and THM:

Stone
Aero
Cure
Protect
Stoneskin
Raise
Thunder
Fire
Fira

That looks like a pretty good Red Mage spell list to me.

Instead, Red Mage should get an ability to enhance those spells to make them more viable.