http://xboxclips.com/Cobravert/1fb87696-70d4-4b40-8ca1-551a2435bd47 When the Enemies Are Moving Against Each Other, in the first spawn area, go to the cave where the Hive spawn. With 1 other person there doing their supers based off your orbs you can both power through a lot of points in the time the event is running. My son was here on this one using his Hunter's tether. I've also come across other Warlocks going Palpatine like I was, and even Titans throwing hammers. You can keep this up the whole time so long as there is 1 other person dropping orbs. Other than that use Wormsinger Rune or Agonarch Rune for some large point rounds, but play cautiously for those AI will wreck you if you're not careful.

You will not get eris Xp from the regular bounties you have to grind coo and she will eventually give you her own bounties

Handing in bounties whilst on the Dreadnaught counts for that bounty as experience gained. FYI - Archon's Forge drops ghosts, artifacts, and class items up to 400LL. I'd suggest grinding that for an artifact rather than hoping for one from a rank up package. Faster and funner. :) Good luck!