1) How can life die? It does not make any sense to me, please help to understand. 2) Why does a person who is drunk fall down does not feel pain but a person who is is not drunk falls down feels pain? 3) why do we say "lehaim" when we toast. what’s the deeper meaning of that from Kabalah point of view?

1. You are totally correct that high-level life, as that of human beings, does not cease and in fact continues after death in this world, in the world-to-come. 2. That is a physiological question you should direct to a doctor or health website, who can easily explain why the nerves and senses get numbed after drinking alcohol. 3. The custom (it's not a mitzvah, based upon the Talmud, Shabbat 67b)) to say "l'chaim" [=to life], stems from the law that in the rare case that the Sanhedrin would put someone to death, they would first give him wine, so as to dull his senses and ease his punishment. Accordingly, we bless that the wine we drink should be "for life", and not the opposite. The Zohar explains that according to the opinion that the forbidden fruit in the Garden of Eden was grapes/wine, we wish to connect to the life-giving aspect of nutrition and happiness, and not to the death-giving aspect, as by Adam and Eve, which brought death to the world.