If just for the sake of balance and QoL, I'd probably make relatively few changes.
  • I'd combine Skill and Spell speed into "Haste" which affects attack speed and oGCD damage (a bit higher than SS's effect on DoTs),
  • reduce Provoke's CD a bit, have spells cancel combo only upon completion, change Defiance into "healing received" instead of only "healing received from spells" and possibly do the same to Mantra and Convalescence, and nerf Equilibrium's healing only enough to compensate,
  • change Grit and Oaths into abilities and halve Grit's MP cost,
  • increase RoH potency to 280,
  • reduce DA cost to 1500 (~17%?),
  • increase Fracture's DoT potency from 20 to 25 while increasing TP cost from 80 to 90,
  • have Flash scale with Fight or Flight,
  • allow Cover's transfer to be toggled while active, use the highest mitigation of self or target, and decrease its cooldown to 1 minute,
  • have Dark Arts-Dark Dance automatically parry any attack that cannot be dodged,
  • allow Soul Survivor to be used on an ally such that you increase the ally's parry and evasion stats or dodges stat by your own (base, doesn't transfer DD bonuses) and either parries or dodges performed by either to proc effects for both (allowing OT reprisal). Self-healing overheals heal the other. If either you or your ally dies, the other receives 20% HP and MP.
  • have Spirit's Within generate MP equal to 50% of its damage dealt,
  • and possibly allow blocks while casting
  • and/or reduce Stoneskin base cast time back to 2.5 seconds, and have its trait instead decrease its mana cost by 20%. (Stoneskin II will be reduced to a 5-second cast, also at 20% less mana cost.)

If from the ground up, though... well, then there's a lot more...