FFXIV - Cross-Class Unlocks

Update (3/29/2017):
I decided to change around this list because more people may be looking at it. Now I've sorted it through jobs/roles/etc.

== Format ==
Level Class    - Skill/Spell (Why/Effect.)

== Magic DPS ==
4  Arcanist    - Physick (BLM Heal)
26 Thaumaturge - Swiftcast (Healers near-require this for level 32+ dungeons for in-battle revive.)
                 (Summoners can use this in case their pet dies on titan/Keeper of the Lake.)
34 Archer      - Quelling Strikes (Because BLM <> Tank Relationships)

== War DPS ==
6  Marauder    - Fracture (MNK/PLD Can use too)
8  Pugilist    - Second Wind (Dragoon/Bard Self-heal)
22 Lancer      - Invigorate (Bard/Monk can use too)

== Healer ==
6  Conjurer    - Cleric Stance
8  Conjurer    - Protect (Lowers incoming Magic/Physical Damage.) (PLD can use.)
34 Conjurer    - Stoneskin (Shield based on Max HP.) (PLD can use.)

== Tank ==
10 Gladiator   - Convalescence (Increased incoming heals.)
22 Gladiator   - Provoke (Sets your aggro/enmity to who has the highest on the target + 1.)
                 (Use Shield Lob, Unmend and/or Tomahawk immediately after.)
34 Gladiator   - Awareness (Nullifies chances of incoming Critical Damage.)

== Mitigation ==
2  Marauder    - Foresight (Increases defense.) (MNK/DRG can use this.)
34 Arcanist    - Eye for an Eye (20% chance striker will do 10% less damage for 20s. Does not work on magic attacks.)
                 (Unusable on: Vault last boss, Elemental Sprites.) (Cannot be used on self.) (BLM/Healers can use.)