Under the Skills menu, mouseover the skill's image and hold Ctrl. This will expand the tooltip to show detailed information. This also works in the skill selection menu and the hotbar.
There is also an option to show detailed information by default. Go to Options > Gameplay and check the Show Advanced Tooltips option.
According to Bashiok:
...faster speed weapons consume more resource but may do more damage. Channeled skills might still be better with slower weapons though because on a channeled skill, you have as much mobility as you want, so the "mobility" and "overkill" advantages of faster weapons are eroded with channeled abilities, so all you’re left with is increased mana cost for increased damage.
So yes, a faster weapon will cause more skills to tick faster, resulting in you dealing more damage over time, but will result in you using up more resources as you are channeling faster.
Channeling mechanics
Let's use Ray of Frost as an example,
Cost: 20 Arcane Power
Effect: Channel a beam of frost that deals 215% weapon damage as Cold.
Since this is a channeled skill. The resource cost ticks by 10 and drains that much Arcane Power at twice the speed of your weapon. If your attack speed is 1 attack per second, instead of draining 20 Arcane Power once per second, it will drain 10 Arcane Power every half seconds.
Additionally, Since Ray of Frost is a channeled spell. It is broken down into many small attacks that deal a total of 215% weapon damage based on your attack speed. If your attack speed is 1 attack per second, it will deal a total of 215% weapon damage per second.
tl;dr: The faster the weapon attack speed, the faster the drain; slower the weapon attack speed, slower the drain.
Damage-dealing
Assuming two weapons have the same damage, the faster weapon will use up resources faster than the slower one when channeling, but the faster weapon will take less time to do full damage than the slower one.
An axe at 15 damage and 1.0 attack speed will drain slower. (15 DPS)
A wand at 15 damage and 1.5 attack speed will drain faster, but will do
the same damage faster. (22.5 DPS)
Best Answer
All blizzards slow enemies by 30%. Grasping Chill has an additional slowing effect after the blizzard is over, by leaving ice on the ground.
Source: My own testing, since none of the books or tooltips suggest Blizzard slows enemies. You will always see "snared" come up on monsters as they are hit by the blizzard though.