That longer explanation helped a ton, Anfa. Thanks for typing that out - I didn't have any other source of information as to what happened.
I'm afraid the list with the quest-requiring items is my fault - at the original time of composition, all the quests were working and there were no NPC problems. I should have modified it before the event start, and this is completely my mistake. Impossible items should have been taken off the list entirely. Again, I'm really sorry for this lapse.
I think the GMs just weren't entirely prepared to take this over for me. They didn't plan the event and didn't have the sort of "inside mini-plans" on how to handle various situations and speedbumps. Thus they were worried and frustrated and trying to balance all these things at once and not entirely attentive - not the best situation, but still a bit understandable I hope.
A lesson, all in all.