Sharpcast isn't underwhelming. It's a pretty fun cooldown to optimise. You have to decide whether getting Firestarter or Thundercloud is more important in that moment on the spot. I enjoy that decision making on BLM and reworking/removing it for a skill just to make Fire 1 instant would sure, amount to generally the same thing, but it removes the fun of having to choose between Fire 3 and Thunder 3. Without timers to facilitate those conundrums, you'd just be choosing whatever's stronger. If I chose Thundercloud over Firestarter and drop Enochian or lost a Fire 4 then... oh well, that's my own fault for not planning it out properly, not the job's fault.
If you want a stress free caster then go play RDM or something, dude.