You're in haven and you switch instances to 5, you then go to the arcade. Is clockworks the same instance (5) or is it random again?
Clockworks and instances
I don't think the Clockworks even has instances. It's just a party of you + other people, seperated from other other people. Yes, I intentionally put two "other"s back to back.
In the Clockworks, each party is running its own instance. There does not appear to be any instancing beyond that.
You're in Haven 5 once you've gone to Haven 5.
When you go to the Arcade, you're still in Haven 5 unless you join someone who's not in Haven 5.
Once you go down the Clockworks, you're not in any Haven. When you return, you're returned to any Haven of your language. I believe which Haven depends on where you have the most friends/guildmates.
Ok, so wat if player [A, B, and C] (already in clockworks) goes to player [D], if item drops are only instanced based, and defeating enemies are seen by everyone in the party, are you half-instanced into the player [D]party? Are item drops different?
Mystrian, I'm not sure that I understand your question, but here's my understanding:
If you're in a party, and a monster dies, and it drops its loot, then you see the loot. The loot that you see may be different from the loot that the other players see. (Certainly this is true of treasure boxes.)
If a monster dies, and then you join the party, then you don't see its loot.
You mean playing in the arcade levels in general? If so, then it's probably random. The clockworks/arcade are not connected to Haven instances.