Some options for improving:
- Varied-time DoTs, one long duration, one short (at minimum). DoT timing that isn't static means there is something more to pay attention to.

- A potency-progressive combo system, broken by hitting the wrong DPS spells, healing GCDs, or healing oGCDs to better plan usage or coordination

- Positionals on spells (DPS and healing), to include frontal positionals to balance casting and movement. Plus the adrenaline rush of a frontal positional on a boss that cleaves. Some people want danger.

- An oGCD potency buff to be maintained by completing DPS combo and positionals (skill potency + buff = current potency). That way there is a penalty to rotation failure or timing, but with a fallback to full-potency GCD heals to do bare minimum.

- Job guage (Lilies, Aetherflow, Addersgall) fed by actions instead of time (keep skills that give a free use). Perhaps based on a step in the DPS combo (e.g. spell 4 of 6 gives a stack, meaning you can re-start rotation for faster stacks at the cost of the higher potency as needed)

- Variance in cast times of DPS rotation. Maybe the big hit at the end is full-GCD cast time to tradeoff higher potency for a single weave window (unless you Swiftcast first). Variance in timing breaks monotony.