Yes. Block is similar to dodge. It doesn't reduce damage but it does block the incoming damage. Dodge is basically making the attack kids but because of DQ physics, dodge looks like it's blocking.
It works the same in all weapons and legends of all classes and that's also true if it's on other parts of the gear such as a Mainhand weapon, chestplate, helm, etc.
Yes yes and last answer is simply, it blocks incoming damage and behaves like dodge affix . Does it block all damage, I'm pretty sure it does block all damage just like how dodge can dodge any kind of damage.