You could check the source of that first statement, and read it thoroughly (and try to fully understand every word of it), it should give you a good estimate of an answer.
I'm saying that because I don't recall where I read that too (about the bonus atkspeed), otherwise I could give you my thoughts about it.
I would assume that's a bonus for everything Dual Wield related, so Barbarians and Monks also get the bonus atkspeed. But it could be just for ranged weapons.
Does that apply to any class that dual wields? Such as, if a Barbarian dual wields two swords, does the Barbarian get a 15% increase as well?
I'm saying that because I don't recall where I read that too (about the bonus atkspeed), otherwise I could give you my thoughts about it.
I would assume that's a bonus for everything Dual Wield related, so Barbarians and Monks also get the bonus atkspeed. But it could be just for ranged weapons.
Whenever you equip two one handed weapons the following happens:
1) Your character attacks alternate between each weapon (even in skills).
2) You gain 15% attack speed bonus