If we ultimately have little to no control of the endogenous and exogenous factors of our lives then to what extent is it helpful being pessimistic. Is not optimism the only sane choice we have? I like to believe so 🍀

I am more of the opposite understanding. However, feel free to agonize over your mortality by trying to solve it as a problem. If transhumanism is your thing and you think that imortality would solve your problem with death then by all means, although I personally would rather put my energy into something else. Death dosen't only have to tragic or sad just as life dosen't have to be tragic and sad.

Your nature and my nature is to die at some time. It's not going against the nature of what is human to accept death as an integral part of existence.

I do not see how this would promote suicidal ideation. If anything then I'd suspect the opposite. A closer relationship to death might make us more content and relaxed with our own humanity.

Death is out of our control, so no it's not a problem. We should however address our strained relationship with death in general. That is a problem worth solving.