Fear and Ledges
As a necromancer player since beta i must say
The thing is… You can. You can “walk” people off the edges. Every edge that you can fall without jumping is compaitable with this. You just have to make a note that when you are fearing your opponent A: he/she will walk thus not going back a great distance B: he/she is walking to the direction directly away from you and C: fear last for 1 sec if not traited (which is kinda sad but I can live with it)
I do this everytime I can. It is all about the timing and you need to juke your opponent near to the ledges. One great way is, if you are fightin against a melee, lure your opponent near to an edge and juke to side and fear him. I suggest using death shroud for fear a single opponent (as this is quickest way to fear and has lowest cooldown and is available for every necro) and extend it with staff 5 if needed. If you are having hard times and really want some cc you should take soulreaping traits fear lasts longer and reduced cooldowns in DS.
Also make a note that chill and cripple will greatly reduce the distance your opponent will walk and immobilize will root him in place (immobilize + fear = a stun, in practice) so be careful not to chill your target if you are planning to walk him off an edge (in other words avoid these when fearing down the edges: staff 3, scepter 2, axe 3, dagger 3, death shroud 2 ). I haven’t tested if swiftness on an opponent increases the distance he walks while in fear. This would be an interesting mechanic to counter swiftness if it works. :P
Swiftness (and any other speed boost) does indeed increase the distance someone travels while feared. I see it happen all the time in WvW.