Well Night crawler teleports, while Grimm creates a portal. Along with the fact he can scry a far away location as to see where he'll end up. That is explained in the power on the character sheet.

Also no Grimm does not in fact have to touch a person to drain them, he can do it over a short radius. 
Though I suppose you're right that it isn't a soul, so much as it is raw energy that's not defined in any real manner. As it's not electricity, or anything else one can inspect under a microscope on the planet earth. Only Grimm's race could see it, as they'd evolved to so they knew if food was there or not. By his own species standards Grimm is an unnatural freak of nature.