I wouldn't necessarily argue it's good design, but it's most certainly possible design.
Possible design is the whole point of this thread. When they're good, we can consider them further.
On that note, I think Gravity is the best of those ideas you posted,
time's notwithstanding. In-element and a bit more unique. The other ones just deal damage (or generate quanta, in Light's case, but Bioluminescence is already a popular replacement for that). Death's effect might deal poison tokens, though, if it would be changed.