You caught my attention. I actually had plans for a coin named suicidecoin.
Proof of suïcide is a concept whereby the coin bagholders kill themselves. Thus increasing value.
Proof of suïcide increases media exposure for the remaining coins by leaving death notes.
I believe that there is a thin line between black humor and crudity. Making jokes about suicide is former, your "concept" is clearly the latter.

I do not agree. Suicide or Euthasia relieves actual suffering. I am an actual suicidal person, and the availability of secobarbital and/or propofol may assist in relieving one of these common pains.
These problems can be solved by linking a messaging protocol with the public keys. For example a PGP key.
A marketplace user(witch doctors) will gain authority by 'death status'. Where as a heartbeat(last signal of existence) x value of the trade × the amount of reviews will validate the user 's trust rating. All these problems can be solved mathematically.
This is a clear instinctric process for the coin to gain value, and to relieve suffering. Witch doctors are a necessary evil for the coin 's survival.
Awesome idea about euthanasia, but please, don't suicide right now, we suicide coins here