There is already punishment for dieing like crazy. It's called "Brink of Death" which basically makes you completely ineffective in battle, in which most important battles are timed.

And, unlike in FFXI where intentional wiping is a completely valid tactic, here death of a group means automatic failure of an instance. So the punishment for death is more substantial here than before.

Again, there's no real reason to do it here, at all. Those who are goal-driven value not dieing, especially those with Sanction. (even after getting a consumable sanction item, it still will be very costly to have to constantly replace it.)

Again, there's plenty cost for dieing, people will be much less inclined especially if more gear like Sanction Gear becomes prevalent.