As long as the current lore and Class --> Job plans stay as they are, CNJ will need at least the following abilities.
  1. Cure
  2. Curaga
  3. Raise
  4. Paralyna
  5. Poisona
  6. Silena
  7. Protect
  8. Shell
  9. Aero
  10. Water
  11. Fire
  12. Thunder
  13. Blizzard
  14. Stone

This covers all healing magic and all the "basic" elemental spells.

The elemental debuffs and the ancient magic elemental spells are not basic. I can see the elemental debuffs getting moved to Thaumaturge, to join the other debuffs. Just looking at their names (Drown, Rasp, Choke, Shock, Frost, Burn) and the actual effect they have (i.e. slowly draining the life out of you), I can see how the development team could move them without disrupting the flavor and lore of either class.

Honestly, the ancient elemental magic spells should be reserved for the Black Mage job, and quested for. Their power should be adjusted upwards accordingly.

This is all just my opinion though.