The Oneness with the universe that Buddhists are after, is really that you try to realize you already are one with the universe, because neither you nor it actually exist. Only Being/Existence Itself (God) exists, Buddhism says.
You do realize that Buddhism, Taoism, Confucianism, and Chinese Traditional Religion/Shinto/Korean Shamanism are all different religions, right?
The way it sort of works is like the various philosophies in Ancient Greece and Rome. One might worship the Gods (that’d be Shinto/Shamanism/CTR), but one would also, if one was not satisfied with, basically, making sacrifices for good luck, one would also belong to an ethical/philosophical group, like Epicureanism or Stoicism (sort of like Taoism and Confucianism respectively) or the Neo-Platonists, Pythagoreans, or mystery cults (sort of like Buddhism).
Buddhism is generally what buries the dead, since its teachings are concerned with salvation–namely, not getting reincarnated anymore.
Taoism teaches a different kind of salvation: by learning the rhythm and cycle of the cosmos, one can become wise enough to become Immortal, and, again, not have to die/get reincarnated anymore.
Confucianism is more pragmatic, but it teaches people to revere their ancestors, respect their elders, and study the classics.
The traditional religions (Shinto/Shamanism/Chinese traditional) are based, more than anything, on the idea of purity. One tries to avoid anything, from dog-poop to dead bodies to resentment to an obligation, that might make one unworthy to offer sacrifices to the gods. Korean shamans (whose gods talk through them) will throw people out of their rituals if, for instance, they’ve just come from a funeral, or they’re on their periods–because of ritual purity. They’re also concerned with living in harmony, but because immoderation creates an impurity.
