the trouble with this is, sometimes the simple literal interpretations were never meant to be taken either simply or as literally, in my own view.
Given sizeable population was illiterate [13th Century], Nanak and all the Banikars spoke to the masses in their own local dialect - use of complex and sophisticated techincal jargon would've defeated the objective with which they set out to achieve. According to the literal rule [Law] it is the task of the reader to give the words to be construed their literal meaning regardless of whether the result is sensible or not. If we depart from the plain and obvious meaning on account of such views [yours], we in truth do not construe the "actual" wording but alter it. Take for example, the mool mantra, in particular the wording, "ajunee". Straight away the mind signals the brain to compartmentalise this ajunee and work out meaning. In its simplist form a "june" is a physical presence of a species within the confines of this beautiful universe and by putting a prefix [a], Nanak negated it to effect its actual and simple meaning, which otherwise is the cycle of birth, death and rebirth. By default, evidence is there - believing is another thing.
I am not so sure, my understanding is that Brahminical practices go hand in hand with Hindu ideology. I do not believe he grabbed something and refined it, nor do I believe that Sikhism is a halfway house between Islam and Hinduism, in my opinion, he fashioned something brand new and from scratch. Any references to Vedic or Muslim philosophy were meant to be references not suggestions nor was he condoning them, in fact, I find most references are made quite tongue in cheek.
What feels right to believe is powerfully shaped by the culture we grow up in. From a Sociologist's perspective, looking at Nanak's culture [Hindu ideas, literature, Art, Science and a shade of Islamite], biological make [Hindu parents, kin, family, friends, etc] and cognitive disposition [mindset - disillusioned with religious belief of his time, i.e Hindu/Muslem conflict and bigotry] one is drawn to conclude how many of Nanak's fundamentals came to shape him from his childhood. The process begins from the moment we are born, based initially on our sense perception. For example, objects fall downwards [gravity] and gradually our sense perceptions expand as we grow to more abstract ideas and propostions. In Nanak's case, not surprisingly, from the belief sysytem he encountered. As social beings, beliefs are learned from the people we are more closest to - this'd be Nanak's parents. And, if I'm to accept your assertion that Nanak started from scratch based on direct experience, then that would defy the law of cause and effect, which is intrinsic to human nature. What we come to believe is shaped to a large extent by our culture, genetics, and psychology. And, as we grow to adulthood, we tend to have a relatively coherent and resilient set of beliefs that stay with us forever.
and should stay very much Hindu
This does not follow that reincarnation is therefore part of Sikhism.
In my humble opinion, you may gain valuable knowledge if you were to study some not all of Sikh History. This will put you on a good stead to understand some of the basics, so that, process of elimnation becomes simpler and absolute. Hazur Sahib and much more has a reincarnation ring to it, which cannot be dismissed without intellectual investgation for the want of respect and reverence - again in my humble opinion.
I have never thought of Sikhism as a leap of faith, I feel it is more pragmatic than that.
I was generalising "belief"
Not all of us believe in Hemkunt Sahib, some of us see it as nothing more than a location that is responsible for much misery in people trying to reach it. I do not accept that Guru Gobindji had a past life, nor Banda Bahadur. It is not even out of subjectivity nor rationality, but out of what I feel the SGGS has taught me.
Sikh institutions and the millions that turn out to pay their respects have a sense of belonging. Of course, you are entitled to your view and belief.
Enjoyed conversing with you brother H, but must put this reincarnation n thing to bed coz there's life out there.
Goodnight and Godbless