True.
Still, they don't seem to be kind who will take evil jobs like bandits would.
Also, you should avoid becoming a werewolf (I've heard a rumor that you can't continue Companions quest-line if you don't; in that case, cure yourself after you're done, or just don't finish their quests).
Also, you can always join them just to get access to Skyforge equipment and then be on your way.
Edit:
I know it's kinda off topic, but after playing a bit with the perk calculator, I came up with http://skyrimcalculator.com/#17757 build.
I call it: Spectral Rouge! :spotted owl:
Still, they don't seem to be kind who will take evil jobs like bandits would.
Also, you should avoid becoming a werewolf (I've heard a rumor that you can't continue Companions quest-line if you don't; in that case, cure yourself after you're done, or just don't finish their quests).
Also, you can always join them just to get access to Skyforge equipment and then be on your way.

Edit:
I know it's kinda off topic, but after playing a bit with the perk calculator, I came up with http://skyrimcalculator.com/#17757 build.
I call it: Spectral Rouge! :spotted owl:
Yeah especially if I remake, Im a breton now no idea why haha. Making a Nord, blond haired, steel eyed named Sigmar "Something", looking at norse names now hehe. Want something that means
dragon and protector or something.
I think they are an honorable lot, and correct me if Im wrong the companions are the ones who freed skyrim right?