2HS vs dual wield

[Pinolian]

When is it better to go with duel wield vs 2 handed as a warrior? I thought I read that duel wield at lower level levels (prior to 30) is not as much damage as duel wielding because of there being such a slim double attack chance on the off hand

And this piggy backs on the answer..
Do you have to use dual wield to generate more hate for tanking?

Thanks in advance