Your question assumes that every life is worth living, and that theonly point to ending one's earthly life would be to "trade up" to apresumably better afterlife. But if one's life is so bad that it is notworth living, there is no paradox in preferring oblivion. Your exampleof a life dominated by excruciating case might be an example where somewould find life not worth living; I could imagine that slavery could sodegrade those who are enslaved that their lives seem not worth living.My sense is that the prospect of avoiding future degradation orsuffering gives suicide salience in cases like these, not just theprospect of enjoying a better afterlife. Socrates' discussion of the afterlife in Plato's Apology is a fascinting philosophical discussion of possible attitudes towards the afterlife.

People who commit suicide can surely do so with the intention ofprovoking political change, including resisting tyranny or injustice. Likewise, those affected by the suicide of others can surely beprovoked to political action by that act, including action that servesto fight tyranny or injustice. However, this seems to me a perilous strategy of politicalresistance, and not just because it involves death. I suspect thatindividual acts of suicide are difficult to structure effectively aspolitical acts: because suicide often baffles those affected the mostby them, the odds of any particular suicide having the intended effectlook to be rather low. The consequences of acts of mass suicide alsoseem difficult to predict, in part because media and governments willsurely subject those acts to interpretive "spin" that will inevitablyserve coroporate or governmental interests rather than those of thereistance group. In sum, death in general and suicide inparticular strike me as such culturally complex...