Re #1, 3 4, and 5.
All of these terms I bolded above, are all words laden with emotional content . It is our "Sapience" which is causing us to use these kinds of words because they reflect the internal feelings we have over things that we consider to be "bad" or at least the inverse "not good".
Death to a non-sentient being has no emotional feeling to awareness. Sapient beings from cats and dogs to dolphins and whales appear to have some perception of loss at the death of another. Whether this attached to instinct or sentience and where the boundary is, of course we don't know.
But if we are implying death in the evolutionary world is bad is a non-sequitur. It is a function of the life-cycle.
The same is applied to killed, disaster, disease, and certainly suffering especially if being applied to non-sapient/sentient beings. If there is no recognition or loss to death, then the terms disaster, disease, and suffering are moot points.
Instead of disaster perhaps cataclysm is a better word as it denotes a violent natural event.
I don't have an alternate word for disease, but if we can use it without the emotionally bad overtones, it will work. (the word itself is constructed from dis(not)-ease which carries its emotional content).
Killed as a word is often used as a synonym of "murder" -- when it is applied to people. And the moral agency is certainly applied because of it. However, that must be distinct from "murder" as killing someone (manslaughter) by a human, has a lesser penalty than murder (in both Biblical and secular law).
As for organisms killing is technically correct, but not with any moral agency to make it bad.
It is easier to assign these words to venues where moral agency is in effect (as @gbrooks9 has pointed out). The problem is at what point does this apply to "living" evolutionary hominids and cetaceans et al.
Good topic! Thanks!