I should say b=c.
When something isn't needed, the simple existence of it is a design flaw.
Is crafting needed during leveling? No, it could be useful, but it's not needed and the work required for this is just too much. Heck... I remember my 14k HP tank Jugg back when I started my first HM FPs, full of blue/green loots and with perhaps some Centurion stuff... but it worked (ok, I died on the -dark- first BT boss mainly because I didn't know it, but we went through it).
Is crafting needed for end-game? No, and it's even becoming totally useless if 2.0 goes live as it was on the PTS.
Conclusion to this? Read the thread title.
Clearly, crafting should not be needed to sucessfully play the game. On the other hand, crafting should make the game play better and you stronger and provide looks and options (love my crafted Hotrigged speeder) that you cannot get from drops. Also crafting = credits and credits = buying good stuff on the gtn that improve your character.
I leveled my first character with no crafting skills and it was a bit of a slog. I just finished my last 50 with full crafting support and it was a fun breeze. I like to craft and build my toons, so work on crafting is well worth the effort. I also like having more credits than I couuld ever spend even if I played the game for another ten years.
As far as the title and your conclusion, I would say that I do not anticipate much change in crafting for pre 50 leveling. I have not been on the pts (although I read a bit of the feedback) and will wait and see what 50 to 55 and 55 cap crafting is like.