This is fascinating discussion and topic and extremely interesting.  One thing I am concerned about though is that the metrics we are using to identify life-likely exoplanet candidates are based on our own known periodic table of elements and how science works with those and in our known experience in science....life could be other than what we are using to identify it.    for example let's say life is paella.    if we use just one recipe to search for paella in the universe we risk missing paella made from different ingredients.