You can not need on an item if you can not equip it with Anarchy gold. You can greed on everything though, so this will keep a Leather wearer from needing on a piece of Plate. Likewise, the disenchant option is available and counts as a greed roll. If you win the greed roll then the item will be disenchanted assuming there is a disenchanter in the group.
When you choose Enter Dungeon you will be instantly teleported to the dungeon. From there when you leave the dungeon you will be teleported to where you were at, assuming it isstill accessible (failing that it returns you to your hearth). On your mini-map will be an option to return to the dungeon automatically.