Right...now im confused lol!!
Is this one of these situations were there are no right or wrong answers?
but I still assume the choices that are better then others?.
Honestly, and I put a lot of effort into this, there isn't any good answer. Crafting is just a big nothing in this game and you don't really need it to make credits as best I can tell. And, what's worse, is that they pile on at the end with a terrible interface, the GTN, for selling anything you do make.
I picked 3 mission skills, send my dudes off, and sell anything they bring back which I like because I never click on nodes. Honestly, though, the GTN is such a pain to use, that I'm regretting that choice too. I didn't take slicing though so I could dump a skill and just go after lock boxes and never have to use the GTN. It's so bad that I'm considering that,
If I continue to seethe over the GTN, biochem is the other answer, because it has some marginal use while leveling, a marginal pvp use as an extra heal when I'm out of the pvp one's, and you can bulk reverse-engineer so it's the easiest to get good purples.
The whole crew skill/GTN/economy needs some serious love that it's likely to never get.
My best advice is to not put too much effort into it, BW sure didn't.