Does Sartre have anything to say about the relationship between being-for-itself and death?

Answer 1

Yes Sartre does. It could be argued that these are one and the same thing, but perhaps more on a metaphoric level than on the plain of reality. If any object or individual is only living for itself, then ultimately it has no existence at all, it is dead not only the rest of the world for which it does not care but also dead to itself. There is no meaning and therefore no existence.

Answer 2

There is a sharp contrast between Sartre and Heidegger. Heidegger was an Essentialist Phenomenologist and Sartre was an Existentialist Phenomenologist. As such Heidegger believed on could find transcendental meaning in the world whereas to Sartre nothing has meaning beyond its context which according to him is completely subjective and therefore meaningless and aliening. As such there is no virtue or meaning if being for itself. Death is meaningless as well.