Q about finding special Set / Unique Charms (unmodded game)

[Pangaea]

(Y/N questions)

1a) The Cow King Set can only found in the cow farm?
1b) The Portal to the cow farm can only be opened once per difficulty level?
2a) Annihilus can only be found by killing Uber Diablo?
2b) Uber Diablo spawns only via modding in single/multiplayer?
2c) Can Uber Diablo be killed by a single player char with unmodded items/char?
3a) Hellfire Torch can only be found doing the pandemonium event?
3b) Padenmonium event isn't available in single/multiplayer?
4) Drops Gheed's Fortune in single/multiplayer?

(non -Y/N question)

5) What triggers Uber Diablo / the Padenmonium event?

[Necrolis]

The cow king set has hardcoded drop flags that allow it to only drop in the cow level. The portal can be opened any number of times, till you kill the cow king(its a 'hidden' quest). Yes for 2a, b and c(though you'll need a strong char like a smiter), and 3a and b. Gheeds, can drop in sp/mp(i've gotten drops off hell andy, meph and baal). Uber diablo(diablo clone actually) is triggered when a certain amount of sojs are sold to vendors(it uses a formula), the pandemonium event requires the cubing of keys to kill the lesser evils, them the cubing of the organs they drop to create the portal to tristram

[Pangaea]

Ok....so i think i have to increase the dropping of war hat, studded leather and heavy
boots by cows and force nightmare/hell mephisto/diablo/baal to drop those 2 unique
charms by chance

[Nefarius]

till you kill the cow king

It doesn't matter if you kill the king yourself, the quest is actually "completed" if anyone currently in your party is killing the king.

[Necrolis]

till you kill the cow king

It doesn't matter if you kill the king yourself, the quest is actually "completed" if anyone currently in your party is killing the king.

yeah, unfortunately, been screwed by many a douche who kills the king...