In this case, the asking for real-life address seals it, but I'd imagine a whole lot of borderline threats have to be evaluated by GMs.
Of course, I understand what you're really describing. It's just amusing that you and I don't imagine normal behavior to be role play, and can conceive of a meeting wherein people bring their Eve personas together in a simulated star system and agree that these characters will then engage in a recursive level of role play.
The difference is between "Ok nerds, log in your eve clients, get on mumble, and undock and press F1 to shoot this guy. Someone pull up the map on Dotlan so we can see where we're going. Someone ping me on Jabber when you found the hostiles." vs. "Capsuleers, please board your spaceships, and prepare to undock and fire your weapons. Gallente pilots, break off formation and assist the Logistics wing!"
Say that to my face in nullsec.
From a RP point of view I find that amusing, from a RL point of view it's troubling.
Eve and its player base encourage RP but don't force it on you. Joining Alliances is usually the easiest way. Political strife and territorial expansion is a really ripe field for emergent stories and personalities.
No, it is trivially easy to make the call when someone threatens harm to another player in real life.
You are right that nobody complains when pilots threaten each other in-character; everyone understands that the capsuleer characters are cutthroat and might try to intimidate each other. This is good fun, well within the spirit of the game. We're all just playing space pirates.
The problems arise when you say another player's going to be missing his hands. It's very clear here that this was the context, since it followed "whoever know[s] his real name, home address and other details [message] me." For an admin of a game, a situation this clear doesn't even take much thought - it's a straightforward reason to ban someone.