This is totally relevant. There is always a chance it is nothing but imagery, but it sounds exactly like one of the common pathways and like you clearly can sense it. I would start any work with that model and get to where you can feel it at will. Then in higher intensity. Then try to influence its motion. For example it can be given a spiral current in either direction as it cascades by applying intent.
I think all of your above thoughts on this are sound and on what I would think of as on track. I can of course not tell anyone else what the truths are, beyond very simple aspects of how I experience it.
Size and location is a weird and hard to grasp aspect. The location of one of these bodies in that field seem unrelated to location in the world. In fact I do not think the energy body is attached physically to us. It is connected, but I feel location is somehow a thing of this world and not related to the physics of this stuff. In a real sense the energy body also extends infinitely into the whole but has a center. that center is the base of its identity and can actually have spacial relationship to patterns in the field. For instance there is a center point of some large source (God? Just some big thing, like the sun?) that I can sense. I can move my energy body to be in line with what i would think of as an accretion disk caused by that thing and also adjust my axis to fit most successfully with it like a planet in a stable orbit and spin.
Size in my jargon does not relate to size in this world, say that your energy body is as big as a house or the city. It is more that it is something that can be added onto. It can be developed in a way that it contains 'more.'
Maybe it is related to a sensory organ or nerves, but I suspect it is a sense of the energy body, so the sensory organ may be composed of this other matter, not flesh. I don't know.
The parallel universe thing is a big part of my thinking. In my experience this is all data sets and no physical world truly exists. Therefore if we look at it as a created virtual world, we now do not have to worry about limits. We do not need to create a new sun each time a new reality is created. Instead it is just a variant version of the program running separately. It makes sense that the energy body may be able to access information from variant programs.
In the end please let me close with: I do not know. I only can relate my experience and suspicions.