Does Stuff Despawn in the End?

No, the chunk needs to be loaded, which means it must be on the same dimensional plane and nearby. Minecraft items only are in danger of expiring when they are loaded into memory.

How long until items Despawn in the end?

Thanks!! Items despawn 5 minutes after you load the chunk. So if you died, and teleported out of the nether, the timer will start once you're within chunk loading distance of your items.

Do items Despawn in the end void?

As with any other entity, an Item that falls into the void takes damage until it dies. The ItemDespawnEvent is only called when an item despawns after 5 minutes.