Then use Twitch. The post said Twitch is allowed. Xbox is compatible with Twitch streaming. If not, external gaming recorder is your only other option.
Items that say Bound (character) or Bound (account) cannot be sold. If bound to account it means you can put it in your shared bank and transfer between characters. Bound to character can't be transferred. Salvage or refine. You can use an artifact to salvage another artifact for some extra refinement points.
Just state a specific time for your group to enter to group up. My friend and I always enter at 20 seconds or 50 seconds until the doors closed and we always get into the same instance.