If a person wants to die, then why wait?
But seriously, you can solve the problem of #3 and #4 by using stem cells to make your brain divide forever, and use computers to store your memory in perfect condition, since brain cells gradually die off.
The problem is... what is "you"? How do you determine whether you are still yourself after a given period of time? Does my solution actually constitute a solution?
Shouldn't we be focusing on a way to scientifically quantify the soul before making ourselves immortal? On second thought, that might not be the best idea.
The problem is that I am not myself a rationalist, so I wouldn't be any good at writing it. Mage: The Ascension is not particularly good for rationalist fanfiction, since it takes place in a universe where consensus reality is true, and thus the scientific method fails as a way to understand the universe, since the laws of physics are determined by how many people believe in them.
Furthermore, the reason I bring this particular fandom up is because the other fans continually tell me that in the game world, rationalism and the scientific method are wrong, even though the books themselves do not actually support a conclusion like that.
Sure, the antagonists of the game insist they lead the Enlightenment, but only by actively suppressing evidence of the supernatural, encouraging disbelief, and utilizing spin doctoring to its utmost maximum (Seers of the Throne 29). The point was less about science and more about convincing ordinary people that the supernatural did not exist by whatever means possible.
A group called the Null Mysteriis even discovered, by examining werewolf corpses, that whatever causes the transformation "does not appear to obey known laws of chemistry, biology or physics: a realization that both excites and troubles" (Spirit Slayers 71). Since werewolves revert to human form upon death, they've considered vivisecting one to better understand the transformation, but many of them find it unethical.
Are non-existent people simply extensions of the existent people who created them? Is not the reason for their creation to forward a point supported or opposed by their creator?