I know there would likely be some balance issues, take it with a grain of salt. Just some ideas.
Class: Fencer (sword; Rapier, possibly off hand parry dagger [Main Gauche])
Job: Red Mage (DPS, THM and CNJ)
Actions: Skills like FFXIII's Aquastrike, Sparkstrike, etc. Combo skills like Monk and Dragoon, say Flamestrike -> Galestrike -> Sparkstrike (additional effects and potencies are debatable, not gonna say any). And various self buffs I guess, possibly enfeeble spells like Paralyze (unlikely).
Cross Class: Fire (no astral buff), Thunder, Surecast, and Swiftcast from THM. Cure, Stoneskin, Stone (no gravity/weight effect) or Aero, and Raise from CNJ.
Job Actions (in no particular order):
Dualcast - Next spell is cast twice. 1 minute recast.
Enspell - Adds additional damage per auto-attack (like Sword Oath). Element changes with last combo action used (sparkstrike = thunder, etc.). Takes MP per tick like Bard songs.
Saboteur - Next Damage over time lasts X amount of seconds longer (whatever's reasonable). 2 minute recast.
Aquaveil - 10% reduction to damage taken, 10 second duration (or burns MP and can't be used while Enspell is up, think Fists of Earth/Fire/Wind. Otherwise 2 minute recast).
Elementa - Spell, burns all MP (or all remaining, like Flare). High damage, non GCD, 3-5 minute recast.
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Dancer - DPS
Class: Thief (2 knives/daggers for the weapon)
Other classes: CNJ and PGL
Class Actions: Various skills for the class.
Job Actions (all dances like bard songs, MP per tick):
Drain Samba - puts debuff on target, all characters who hit with an auto attack regain a small amount of HP. Can't be used with other dances.
Mincing Minuet - Like Sword Oath, can't be used with other dances.
Climactic Flourish - Ends current dance and drains all MP, restores up to 400 TP depending on MP left. 5 minute recast.
Dancing Edge - high potency off GCD, 1-3 minute recast. Put's 30 second DoT of 10-15 potency.
Heathen Frolic - Reduces enemy STR and INT by 10%. Uses more MP than other dances.
Would have put haste samba there, but I recall Yoshi-P saying we won't get any form of haste =/