The entire process you describe does sound familiar, though I can't really say that mine is exactly the same. Most notably I don't think my writing process can be described as having phases in the first place; I tend to jump back and forth between writing description of events, picturing them in my mind (often one fragmented image at the time, expanded only as far as the context requires it to be) and writing background information and indirect thoughts. Although often (as I know you do as well, Shien) my process will also be interspersed with breaks for physically testing various movements with my own body (and occasionally consulting someone else on whether it works the same for someone with joints with normal mobility) and muttering dialogue to myself to test the time it would take to say it and help me imagine how it would be said (interestingly, I seem to have much harder mentally reproducing sounds than I have images).
I never realized that not everyone has a "mind's eye", as you call it, but I guess it makes sense.
And yeah, Shadow Image (and the different-nature spells that share it's incantation, the names of which I don't remember because - I just realized - the document in which I had recorded spells in was lost in a recent reformatting of my PC; I remember only that there were three in total, and that the other two manifested for light-affinity and other affinities, respectively) does work very similarly to that. I also imagine that a "mind's eye" would not only make it easier to do it, I figure it would probably be impossible to do it without one. The same goes for teleportation, unless the target location is somewhere magically marked in advance rather than mentally selected during casting.