Certain ones I know you can handle, others I'm not too familiar with.
The Brachypelma are either a hit or miss and I know they like to flick hairs.
When I owned a G. Rosea I used to handle her all the time, same with the Pink Toe(A. Avic).
As far as holding an Emperor, I'd be more worried about being pinched then stung, as that's their first means of defense. I've heard an Emperor can crack a pencil(though I'm unsure of how true that is) and the sting isn't any worse then that of a bee as the excitement hurts more.
You just have to know what you're doing and be comfortable and familiar with species and how they react to certain things, a general rule to scorpions/tarantulas is once they're on your hands, your hand = the ground. They don't sting the ground so if you're switching from hand to hand then make sure you keep your hand flat with whatever else.
However I would never recommend to anybody to hold scorpions and/or Tarantulas because you might be allergic and not know it.
Edit:
Great pictures Tiff![]()