But I am refuting the metaphysical premise that there will always be representation. Representation without animal minds is not possible. So your move is to say mind is somewhere not in animals. This is always the paradox Schopenhauer and idealists and perhaps Buddhists must contend with. Otherwise, the “nihilistic” solution of passively not procreating would technically end suffering within a generation for the animal who has self awareness about this. That is to say, the unborn truly is being never born. That ends the cycle. — schopenhauer1
1. My take is that Zapfe and Benatar (not sure I've spelled them correctly) are materialist philosophers - and if you're nothing other than a physical body, then when the body dies it's all over, that is the end of it. If nonbeing or nonexistence is the final end, then that is all there is to it. There is no 'problem of existence' to solve if you don't exist!
I don't know where Schopenhauer stood on the question of life after death, but I'm sure he would not envisage any such state as 'eternal life' or an immortal soul. But he also hints that the attempt to escape from the sufferings of life through suicide cannot be successful. The relevant passage is
someone who is oppressed by the burdens of life, who certainly desires life and affirms it, but detests its sufferings and in particular does not want to put up with the difficult lot that has fallen to him any longer: a person like this cannot hope for liberation in death, and cannot save himself through suicide; the temptation of cool, dark Orcus (i.e. 'underworld' in Roman mythology) as a haven of peace is just a false illusion. The earth turns from day into night; the individual dies: but the sun itself burns its eternal noontime without pause. For the will to life, life is a certainty: the form of life is the endless present; it does not matter how individuals, appearances of the Idea, come into existence in time and pass away like fleeting dreams. — WWR§54
As the will is what is eternal, I guess this means that it will always find a way to be born, and, insofar as we identify with it, we will be carried along with the tide. Unless you're truly de-coupled from that urge - which S. says is the aim of asceticism - then you haven't succeeded in any real liberation.
2. As far as Buddhism is concerned, the two 'erroneous views' of life are nihilism, on the one side, and eternalism, on the other. Nihilism is not hard to explain - it's the view of materialists, for whom there are no consequences ('fruits') of actions after this life, the 'body returns to the elements'. There are many variations of nihilism given in the texts (Buddhists love lists and compendiums) which include the 'belief that life is due to fortuitous causes', for instance. (From the Buddhist point of view, many modern people are nihilist.) 'Eternalism' is a rather more difficult idea to convey, but my interpretation (and I did do a postgrad thesis on it) is that it is the idea that through meritorious actions, one can be reborn in fortuitous circumstances forever - that is, always continue to enjoy fortunate rebirths. (In the social context in which the Buddha lived and taught, there was an existing acceptance of re-birth, and also, it is said, ascetics who were able to recall previous lives.) 'Eternalism' is also associated with the idea of there being an unchanging essence (often described as 'soul', although I question that), whereas everything knowable is always subject to change (the well-known impermanence, anicca, of Buddhism.) So eternalism is the idea that there is an always-existing entity that can go on forever.
But nibbana (Nirvāṇa) is neither ceasing to exist, nor continuing to exist. Both of those, at root, are
desires - the desire not to be (because of the burdensome nature of life) or the desire to continue to be (because of the pleasurable nature of life). So those drives are, at root, hatred or aversion, and desire or attachment (two of the 'three poisons', the third being stupidity or delusion. However, it should be mentioned that the canonical text which describes all this is the longest text in the Pali canon and these are obviously deep and recondite matters of Buddhist doctrine.)
3. As for the nature of mind - this is obviously a very deep philosophical question. But overall, this is where I find myself most in agreement with Schopenhauer - that objects exists
for subjects. I've thrashed it out in any number of thread here over many years, so I'll just try and present a very short version. You will object, 'but surely this entails that the Universe didn't exist before living subjects. How can you justify that, when we know that living organisms, especially sentient organisms, are very recent arrivals?'
My answer to that is that: no, the world does not exist outside our perception of it - but neither does it not exist. 'Existence' is a compounded or complex term, describing that which comprises objects of perception and also our cognitive systems which assimilate information from the environment and generate our sense of the world, and which provides the cognitive framework within which the very idea of existence is meaningful. (Hence, 'world as Idea'.) That sense of the world
is the world. It's no use asking, 'what happens to it, if we don't exist', because we cannot but conceive of it, or of anything, in the absence of that, nor can we really get outside of that to see it as it would be with no observer whatever. None of which negates the
empirical fact that your or my consciousness only came into existence in very recent times. (I know this is a right can'o'worms, but there it is.)