They seem to be basically saying the same thing.
But none of them say "You can be it".
Well, actually yes they do say that same thing, if understood at the deepest level. Mitchel's translation is considered to be more poetic, and less literal, but it is still highly respected and one of the more recommended translations. He does add the meaning that he feels there in it, as do most translations. But not without justification.
The one I am getting later today is considered a more literal translation, but the issue with this is that if you as a reader, are a stranger to Taoist philosophy, would be unlikely to get the meaning of the texts, as you have no context as a Western person, whose life philosophies are very foreign to Taoist concepts. All translations reflect the translators themselves in them.
So pitting translations against each other is not the most fruitful exercise. I only added his, and the other ones I have as points of comparison for better discerning the meanings of those passages. I consider Mitchell's take to be entirely valid to say "You can be it."
Why? Here's why. Big picture. Taoist philosophy, is very akin to what you find in the nondual schools of Advaita Vedanta in Hinduism, as well as the nondual schools of Buddhism exemplified by Nagarjuna, as well as in the nondual schools of Christian mysticism, exemplified by Meister Eckhart. What you find in all of them is that the highest realization of human consciousness is to be "One" with the Divine, or Emptiness, or God, or whatever word you wish to use.
If you are in fact One with God, that as the translations you used say, "we treat them as The One", or are merged in the One", then you yourself, are That. As the the Hindus say, Tat Tvam Asi, or "Thou art That". That is exactly what Mitchells means by saying, "You can be it". Your identity shifts away from the separate egoic self, or that which is named, as the naming creates the "ten thousand things", or the world of form, and dissolves into or merges into the Tao, or God. At which point, "You are That". There is no more separate self.
This is a fundamental understanding of Eastern thought, in Taoism, Hinduism, and Buddhism. But we in the West see reality fundamentally in dualistic terms. "This and not that".
What I hear you saying, is that 1+1=2. Or, this word, plus that word put together, make a new separate 3rd word. I note that you did not dispute my analogy to the mystery adventure analogy of an Indian Jones like story of 2 stones together illuminate a 3rd spot on the wall which leads to a hidden treasure, as analogous to your treatment of scripture. I will assume that is was a valid understanding of it then, since you did not dispute it.
In Taoism, Wuji, gives rises to Taiyi, from which Taiji is created, the world of opposites in Stillness. But when set into motion this then becomes the world of Yin and Yang. This is the form. The more out of balance we are, the further away from the Source we become. The more suffering we endure. The more conflict arises. The goal is to get back to Taiji, that perfect balance of opposites, and then dissolve into Wujii, or the Formless Source.
It is there, that "You can be it". There is nothing but the One. And that is consistent with your translations as well.
Sounds like the saying "ignorance is bliss". Is that the type of letting go that you are talking about?
Dont worry about the details, just enjoy the euphoria of feeling part of the incomprehensible.
That sounds like faith.
No. Not that. This goes beyond not worrying and beyond faith. You could use the term "Divine ignorance", as that is not the human kind of 'ignorance is bliss'. But even that can be confusing to the thinking mind. It's seeing without judgment, without dividing the world into this or that statements. It seeing through world of form of "the ten thousand things", from the Source. It is an ignorance of duality itself and the dualistic mind. It sees form as One.
And it also goes beyond feelings of euphoria. To quote a favorite passage of mine from the Buddhist Dhammapada,
Wanting nothing
With all your heart
Stop the stream.
When the world dissolves
Everything become clear.
Go beyond
This way or that way,
to the farther shore
Where the world dissolves
And everything becomes clear.
Beyond this shore
And the farther shore,
Beyond the beyond,
Where there is no beginning,
No end.
Without fear, go.
This is not at all "ignorance is bliss", nor religious faith, as all those still reside in the world of thought. It is a state and condition of conscious awareness and being itself.
But circling back to your original approach to using scripture. Assuming you do not reject my analogy of the Indiana Jones like comparison, what your approach is doing essentially a type of divinization, which is at the bottom line, simply a meditation device in order for the active, discursive mind to begin to "let go" and allow the subconscious mind to reveal its own insights that are normally buried under the active thinking mind.
While this may be useful as a meditation device, or as a tool to learn to sense into your intuitive self, or that "faith" that resides in us, it has nothing to do with what you quoted about the "three becoming One". That is referring to dissolving distinctions. All you are doing, is adding another laying of distinction, a hidden distinction, or a hidden meaning. This is not what the Tao De Ching is pointing to, but it is much more akin to the I Ching, with its systems of divination.
While you may be able to create a meditation system like this for yourself, to "defocus" your mind and find new truths, that is a beginning stage of meditation. Letting go and dissolving into the One from the many, requires letting go of everything, and then finding yourself in everything and everything in you. "I and the Father are One", carries a whole new meaning, when understood as nonduality.