1) Olly and the other agent show up available to use the speak with dead amulet, but you can't talk to Olly on the other person in the cave.
2) if a party member dies and you go back to camp via fast travel, the entire party disbands. If you take a fast travel back to the druid grove ( in this instance my closest point to where I was) with one person, 3 people go to the last point you were at while the one person goes to the way point splitting the party even further.
3) You cannot click on the furthest party member to go to where they are in the map. You have to either use the camera to get to them or waypoint over to them