'the realisation of nonduality' - if my ego doesn't exist, why do I think it does?
Instead of "the ego doesn't exist", think rather that the ego exists in the same way as words exist and concepts exist. It exists only as a construct of your mind, a tiny fraction of all your memories that you have access to at any one time, the story you tell yourself, the image of yourself in third person, made up of all the photos you have seen of yourself, all the the times you've seen your reflection, all video footage of you, your body as it appears to you when you look down at yourself.
You believe in your ego because ever since you were a child, people have told you who "you" are. They gave you a name. They reacted to you in certain ways. Certain behaviours were rewarded, certain behaviours were punished. You identified patterns between your own experience and the experience of other people you observed and identified yourself as a "skeptical person" for example, because that is what people who you saw as being similar to you were called, and you wanted to identify with them.
Just like people mistake the construct or the abstraction of concepts and words for the thing these symbols are trying to describe, the ego is a symbol that is an abstraction for who you really are in totality.
If oneness is the truth, why are we stuck in 'two-ness'?
I believe the answer to be tied to the nature of consciousness itself. In order to have an experience at all, there must be the perception of "self" and "other". But according to the Big Bang we all derived from a singularity, the process that is causing the expansion of the universe is the same process that drives evolution and growth of life.
And what do these New Age buzzwords actually mean? What is nonduality? A feeling? A state of mind? An altered state of consciousness?
Well if you had really "done your homework" you would know the answer to this. Using these Nonduality is a word used to describe "everything that exists, without the separations of concepts caused by the human mind". It's called non-dual because it's not-two, but it's also not-one, since it's beyond all concepts and inclusive of all concepts.
Nondual awareness is the realisation of this. It's a shift in perspective. It's hard to put into words because words inherently are dualistic, they chop things up into discrete ideas and categories.
Just a quick example: in extreme psychosis you can get people who think they have become God/everything - how does such a state compare with 'nonduality'? Have these people gone beyond concepts, beyond logic, and into the void? Is it desirable for us to join them?
In nondual awareness the realisation that you are the universe/one with "God" isn't the realisation that your ego is God, or that you as a singular individual are God to the exclusion of anyone else. Inherently it's the realisation that EVERYTHING is equally "divine". You're as much God as a cockroach is God. It also doesn't grant you any ability to do supernatural activities. If someone believes that they are special, as an individual, and that they have special powers due to psychosis, that's not the same thing as nondual awareness.
However of course some mentally ill people can go beyond concepts or into the void permanently, and some of them can also access mystic states of nondual awareness easier than lucid people. The great thing about being sane is that you can do BOTH. You can use your right brain, and your left brain.
'Feelings' (of whatever kind) are a dead end - everyone can have feelings, strong or weak. They tell you nothing about the nature of existence, other than how it feels to feel them.
Everyone has feelings yes. Everyone has thoughts too. Feelings and thoughts can be equally delusional. They also are both essential to human survival. It's a mistake to think there is a hard and fast difference between "feelings" and "thoughts". You are assuming feelings just means emotions. But it also means experience. It also means sensory perception. You "feel" that you are alive. Does that mean that you aren't alive? Are you going to say that your hands and eyes are completely useless because you "feel" through them? Thoughts are your left brain's interpretation of sensory awareness and emotional reaction. Without emotion or sense perception, without "feelings", there would be no thought. Likewise sometimes emotion can be the way that the right brain communicates since it's not chopped up into little pieces and reified like thoughts are.
The people who want to join Daesh have their feelings to, and as you say 'it clearly worked for a lot of them'.
You're better than this cheap shot. It makes you look like you're not arguing in good faith and that you don't respect me. You know very well that I wasn't saying that "all feelings are equally valid" and that "all actions are equally moral". To try and claim that because I said Krishnamurti's attempts to help people achieve nondual awareness "worked for a lot of them" means I somehow support ISIS is ridiculous and is a leap of "logic" that by your own metrics you should be above.
New Age spirituality is a complete fraud - I should know, I was a stoner for ages.
I have news for you, but just because you were a stoner doesn't mean you somehow have the ability to read every single New Age spiritual person's mind and know their intentions well enough to say "it's all a complete fraud". That's fuzzy thinking and you should be better than that.
