The Tibetian Book of the Dead contains a description of the concept of the Lord of Great Compassion who is available to aid in the salvation of humans in death.
This concept has relevance to your passage:
"Buddhism as such may somehow be conceived as theism whose Deities (or devas) are not far from man but as a nucleus latent in every living creature. They only come into being and in sight of those who have possessed a universal vision. "
The 'Tibetian Book of the Dead' Buddhist diety is available for all to help attain salvation. One only needs to ask for it. The Tibetian Book of the Dead also claims that no human has the power to attain salvation him or herself. Normally a Buddhist would appeal to the guru for aid, or even to family or close friends. But the Lord of Great Salvation is available for all humans, whether buddhist or not. The dying or dead person only has to ask the Lord for such help and at the same time do one-pointed meditation on the bright lights that come in death.
This teaching of Tibetian Buddhism seems closer to the teaching of Jesus and Christianity than to what you are describing. Can you comment on the relevance of the Lord of Great Compassion in your belief system and whether or not it correspondes to the Christ diety or is somehow related to a Buddha diety?
For example, a "universal vision" as you say above, is not required by the Tibetian Book of the Dead to invoke that diety. You say:
"This Divine-omnipresence is the essence of the world and, though not openly expressed, is latent in all and everything, extant or not extant. It transcends all categories and limitations; however, it will only be revealed to those being free from the veil of illusory phenomena, those who fight and win pure love and wisdom over earthily desires obtain this inner-self to be one with that of the universal. "
This devine essence is essentially what I call God, being rather close to 'god is everything' or 'god is in everything'. But I perhaps for selfish reasons tend to accept the Hindu and Christian idea that what you ask from god you may receive, including salvation. The Tibetian Book of the Dead seems to support that belief.
So is that book correct Buddhist teaching? Is your Japanese version superior to that Tibetian version of Buddhism? Perhaps death removes the veil automatically. But to do so in life requires defeating the earthly desires. I believe that is the case.