I'm calling tl;dr on the entire thread, so it's entirely possible that my thoughts have been brought up at least once. Please forgive me.
First, who is to say that the Materia system is supposed to be a grind-fest? Perhaps it is instead intended to be done in parallel to every-day activities, such as leves, dungeons or NM hunting. Maybe I use the gear I have until it is time to upgrade, then at that point I convert my old gear, go about the process of getting it attached to my new gear, then away I go adventuring again. Then again, maybe it doesn't take that long to get gear to the point of materia conversion, tempting us to go ahead and convert one piece of gear and buying/crafting and identical piece to continue ranking up towards the aforementioned upgrade rank.
Secondly, We already know that gear can be converted into materia which can then be attached to other gear. But what comes of the gear to which the materia was attached? Can it then go through the same process and eventually be converted into materia also? In other words, can gear that has an attached materia also be converted into materia at a later time? And is the effect cumulative?