that is not possible anymore since they added a minimum CD of GCD to shot.
whitehit speed cap is 0.5 seconds(2 hits per second), so a wdn/d would be doing ok dps, but nothing like the video(relatively).
Yes, this was changed shortly after warnorken arena came out.
However, there is a command code in game to see what your attack speed currently is, however i've lost that and can't remember it for the life of me.
But yes, you can increase or rather, decrease your AS and CS through use of, skills (generally item set skills and the unique class specific skill, and elite skills), potions (they do not all stack together, some skills over-ride potions and some potions over-ride other potions), and certain pet's have skills that will give you short buffs to AS and/or CS.