bad idea in this game. Lack of going out on your own to gather is definatly going to make anyone whos doing a crafting not mind doing it. Your best bet is slicing which the missions give good credits by themselves. Also i think its treasure hunting that gives schematics for crafting will be worth alot. Other then that I might suggest going biochem/bioanylsis due to the amount of money youll "save" end game by not buying flasks and potions and stuff. Really with crafting be a large majority can be done self sufficiently by standing on the imperial fleat means its not going to be a money maker really unless you get rare schemetics or become first to reverse engineer the best things.
You are mistaken. Blue mats will sell like hotcakes especially right off the bat. There will be those that try to learn as many purple recipes as possible...and what do they need? A TON OF BLUES.
All of the blue mats you can gather/farm WILL sell, and at times.. for a lot of credits.