In part these changes are needed. Given the changes in the SP curves at low ranks, and the introduction of bonus SP from rank 1 to 24, people spend less time at the lower ranks. In turn, this means that the value of lower ranked gear is diminished (because it is used for less time). So, the recipe changes make perfect sense for ranks 1 to 30, in my opinion.

Additionally, the level of complexity in crafting FROM RANK 1 is probably too high. Most games work on a progression system that starts off simple, and slowly adds complexity, along with the mechanisms for the player to learn how to utilize that complexity in order to generate more satisfying play. Currently, there is a lot of complexity tossed in at the very beginning of the crafting experience, and it doesn't really get much more complex after that. Starting new crafters off with a simplified crafting system makes perfect sense in this regard (in my opinion).

Regarding the limitations of the market system. While it is true that the market system could be improved to accomodate trading of parts, there ARE alternatives. One idea that occurs to me is to utilize the crafting guilds. Currently the crafting guilds sell a modest variety of parts and materials, but generally only at mid-level, and only at a premium price. If the already implemented "task boards" could be adjusted to provide tasks to produce various parts and materials, and then those same parts and materials were made available through a "craft guild market", this would provide a mechanism for the exchange of parts and materials, without overburdening the already-struggling market system.

For example, wooden handles would be a natural task for the CRP guild. So, a player that is looking for a wooden handle would know to travel to the CRP guild in order to buy a wooden handle. The CRP guild could offer tasks for player crafter to create the wooden handles when "the stock gets low". In this way the crafting guilds could still play a role in the social fabric of Eorzea, parts could be made available (in a way that does not "compete" with crafters making parts), and everyone could be happy? Probably not, but maybe a little bit.