I have to reject your definition, or any definition, that links religion to "sacred" things.
You're welcome to do so as you please, but I offered that definition because Durkheim is one of the most influential scholars in the study of religions, and his definition captures elements of religious practice that are generally recognized as important but that get left out of your version of things.
I have thought for a while that we create false distinction between "sacred" and "mundane" things. If we have spirit, then everything you do is spiritual.
Ah, but that's a personal opinion, isn't it? I understand that in your pantheistic view, there may not be a distinction between the sacred and profane, but every organized religion in the world
does make that distinction. (Even neopagan practices generally involve setting up an altar or sacred space to distinguish religious/magickal practice from mundane life.) It's a fundamental part of what religion is.
Once again, if you're talking about being "spiritual", that's another matter entirely. But spirituality and religion are not by any means the same thing, and as I understand it, this thread is about Tarot as a religion. To that, my answer remains a firm "no" (except, as previously mentioned, with Thelema). If you want to talk about Tarot as spirituality, then sure, go for it. Spirituality is a wholly personal thing, and there's no one who can tell you whether your individual connection with the divine is or is not correct.
As to the community of practice, is that not what we are forming in a way? To form rites and commonality we must communicate and find out what we need.
Unless you're creating a Tarot church that meets and prays on a weekly basis, are structuring group rituals around Tarot cards, are invoking Tarot cards at weddings and baptisms, and so on, then no, that's not what we're doing. This forum provides a social platform to discuss the use of Tarot cards, yes, but that use differs wildly from the rites of religious practice. Moreover, I think that most readers would not agree with the contention that we "need" to create such a religious practice.
Once again, if Tarot is becoming an increasingly important part of your spirituality, that's fantastic, and no one on earth can tell you it's not valid. But in the wider sense, moving beyond you as an individual and talking about the larger world of Tarot readers, no, I do not think that Tarot can be accurately labelled a religion.