Im statching my head. Id have a full reply when I get home. Manifestations of The Buddha is not manifestations of different people who are enlightened. Nichiren Daishin said he was enlightened as a votary of The Buddha. He found his understanding of life through Daimoku. Jesus found enlightenment after he was baptised. I dont know other stories but each person had their enlightenment.
The Enlightenment (not any enlightenment) of The Buddha was complete understanding of life and death and, thus understanding of suffering and rebirth. There is no god. The Buddha's teachings is about training the mind not finding an spirit or inner spiritual feeling in the heart some call god.
He was literally rejecting god and saying everything you, Bahaullah, Muhammad, and I etc experience are from our minds. When we have untrained minds and drawn to things like gods and acetic practices such as the Hindu traditions he opposed you fall into illusions and attachment.
According to The Buddha's teachings, right now you, Bahaullah, Aunt Mary, and Uncle Bob are attached to your religions rather than addressing suffering from the root: the mind.
Religions of abraham talk about The Heart. Old school Buddhism talks about the mind. Two totally different sources. You can use enlightenment if you like but there is a huge difference betwee Bahallauh enlightenment and The Buddha's Enlightenment. The former Bahallauh, jesus, muhammad, etc had revelations via god as the source.
The Buddha transend an dependence on an outside source to understand the nature of suffering. He said address the self.
The Buddha has over thousands of discources. Each one I read so far talks about the mind. It does not mention anything about a creator (to make it more specific). In buddhism, there are more than one god. There are devas and so forth.
Every single person, god, deva, etc are all on the same level. They all hear the words of The Buddha to be enlightened (understanding of life NOT union with a creator)
When I get home, I will address the quotes you gave. But cirst you have to understand the foundation of Buddhist teachings from a Buddhist perspective
Not Bahallauh and not your own.
Peace happens when we stop associating other peoples beliefs in our own when they factually do not belong. Seeing it spiritually is one thing but why and how woule The Buddha manefest into Bahallauh when Baha..believed in god and The Buddha did not?
That means he just turned into someone else. That isnt what The Buddha taught.
Later...
Only to add that each Educator teaches or specializes in a certain teaching such as Buddha - the mind, Christ - love and forgiveness, Muhammad - formation of a religious society and One God, Moses - the Ten Commandments, Baha'u'llah - the oneness of humanity. All these truths are complimentary not contradictory and we can embrace them all but it goes without saying that the further back we go in history the more difficult it us to ascertain Originality thus the Educators all of them have always prophesied One to come after them Who will renew the truth and clarify any misunderstandings or controversies.
All religions await a Promised One not just Buddhists. Christians await the second Coming, Muslims the Mahdi, Zoroastrians - Shah Bahram, Jews - the Lord of Hosts and so on. Baha'u'llah announced to all the world that He is their long awaited Promised One.