Thank you for starting this very important conversation.
For awhile now, I've considered "religion" to be a word used by an observer to describe someone else's spirituality -- even when that other person is the observer himself. Spirituality is essentially a subjective experience; its form, our conscious impressions of it, are "objective," dualistic, separate.
There is a lot deviltry possible in the confusion of these concepts. The popular notion of worship as hierarchical is rooted in this confusion, and it is absolutely demonic, in my opinion. Worship is simply love in its highest degree, and love doesn't concern itself with hierarchy. Indeed, love lays down its life for another. I think the basis for bowing down to God lies not in any sense of hierarchy, but merely in subjective realization of His nature. It's not done because it's expected or commanded; it's not even a conscious decision. You just do. But to the observer, it appears as the result of distinct decisions and actions; and seeing it that way superimposes the subject-object dichotomy (dualism) upon the event. I think you have to look at worship the way you'd look at loving life partners; they optimally don't worry about who's in charge, but work together in harmony, two binary stars revolving eternally around one another.
As a Westerner and a non-Hindu, the notion of japa is counterintuitive. I was introduced to it through Ma, and was astonished to find how effective it can be, even when done poorly.
As Ma frequently says, "God is One, there is no other," referring, I think, to the transcendent Bhagavaan, of whom all the individual gods and goddesses are merely "His" manifestations. Personally, I don't consider these "less thans." Have you ever read "Flatland," by Edwin Abbott? In its pages lies an intriguing concept that explains multiple manifestations of a unitary divine better than any other concept I've encountered.