The frozen shades went away after a quest was turned in, at least thats what my husband said. Hope that helps you out, though I do agree they get a tad annoying.
For the zombies, RP wise it had tons of potential but, the forced issue is what became a problem.
In regards to the griefing/harassment, due to the forced nature of the event it was borderline. As it interferes with regular gameplay. Essentially those people that were complete jerks about it screwed it up for those who were keeping up with the true intention of the event. I can't tell if it was supposed to last longer but it seemed cut short.
This is another Policy:
Zone/Area Disruption
This category includes language and/or actions intended to disturb groups of players or areas of the world, such as:
Disruption of player sponsored events or gatherings
Excessive use of in-game sounds or visuals
Excessively casting spells with noticeable effects in crowded areas
Impeding or blocking access to an NPC, doodad, doorway, or any other area of the world that a player would normally be able to access
If a player is found to have disrupted an area of the world or a group of players, he/she may:
Be given a warning
Be temporarily suspended from the game if behavior continues