IMHO, the game isn't dead yet, and the Hunt does actually have potential - as a proper Hunt.
However, these concerns need to be addressed, both in terms of game mechanics and community building.

I'm sure the Devs are taking into account all the feedback that's flowing in during these first few weeks (both Yoshi-P and Komoto seemed to be aware of it during the last Live Letter).

Aside from rebalancing seal/gear drops, the chances for zerg rushing might be lessened by adding situational factors. Someone mentioned initial invulnerability, others instancing, I would add licensing (a finite number of times per week) and prerequisites (completing intermediate objectives to unlock the actual mark).

Lastly, we need the elite Marks to be smarter. I'm thinking back to FFXII; there was always a situational factor or an attack pattern to surprise you. Top Marks required good planning and some luck; another thing FFXII did right was that you would always gather fragments of lore along the way.