Are we just a measurement device that interacts with quantum wave function/photons or something more? if not then can we die/be destroyed as observer?
I think its safe to say that the vast majority of people in the QM field generally ignore this question (what is an observer/observation) as nonsense in the first degree. We may not understand wavefunction collapse (assuming it exists) but that doesn't mean you have to invent nonsense to explain it. You may not know exactly how your car works either, but you can still drive it, you don't have to imagine unicorn horn in the gas tank.
I say this because in my own brain I simply assume that the entire observer issue is not really an issue, and that someday someone will "figure it out". And when they do, all questions of this sort will simply disappear. It will become like "how fast does a dirigible need to fly?" the day after the 747 entered service.