To raise the question about whether the emperor is walking around naked as a jay bird:
If you want to talk about spirituality, or spiritual dimensions of aikido, or whatever, why involve O Sensei? Why not start with what's actually there in your life and in your practice, rather than trying to go back to the source, trying to figure out what his experience was, and then trying to force an interpretation of your actual experience to fit what you believe O Sensei's experience was?
I have never seen the sense in a fundamentalist approach to aikido. A fundamentalist approach looks at O Sensei's teachings and tries to figure out what they were and go from there. If the evidence of your very senses contradicts what you think O Sensei's teachings are telling you, then you have to ignore the evidence of your senses and cleave to a "truth" that you don't experience. That's the basic problem with fundamentalism of any kind, as I see it, and it's not for me. But if you're going to go there, surely it's essential to discard your preconceptions, develop your sense of what O Sensei was teaching through rigorous research with primary sources (not second- and third-hand interpretations and assertions of what it all meant), and above all, to discard the biases that lead you to an interpretation that agrees with what you want to hear. If your research tells you that O Sensei's attitude was "Shut up about the spiritual stuff, just train," then you have to go with that.
Back to the emperor and his clothes: if you want to explore the spiritual dimension of aikido, the only way that makes any sense to me is to refuse to resort to the authority of O Sensei or anyone else, and to explore your own experience. Figure out what "spiritual" means. Then figure out if it's in your practice. If it isn't, does it need to be? So many times when I see people labeling their activities as "spiritual practices", I wonder if they've really thought about what that means, or if the tail's wagging the dog here and they're not just succumbing to the desire to make things special. You can't make things special, they either are or they aren't, and if you try to tell yourself that ordinary things are special, you're headed for trouble - what Chogyam Trungpa called "the third lord of materialism", where your need for special experiences and states of mind leads you to lose connection with reality and lie to yourself about what's really going on. I've had amazing "wow" moments on the mat, I've also had them walking down the street or riding the bus or whatever. They're great moments. But if you chase them and try to capture them, if you get on the mat or walk down the street or ride the bus with the expectation that they will happen and the belief that this must be a "spiritual practice" because you once had a "wow" moment doing it, you're deluding yourself.
There are such things as "spiritual practices", but there's really no need to try and make every ordinary activity into one. In fact, it's a lot saner not to.