The game is going to get more small updates and a new dlc at some point. So it'll be awhile before the devs stop adding extra content to it. As for the character/companion endings those are all the same still. The succubus ending is still intentionally left open. No change to that ending since you last played.
Yeah you can get her in ACT I as well. After you complete the "Mysterious Letter" quest, go to the north plaza in Summeredge. This is the map zone right above the zone with the inn and entryway. Walk up the steps that lead towards the noble houses/castle, and Carys will come out of hiding and have a small cutscene with the player. That will start her recruitment quest "A Cure For Seren".
For Rilke, I made a little guide, note I did this as a male character. I don't know if it changes for female characters. I always try to be respectful beforehand just in case as well.
After doing Rilke's ingredient quest, go back to cabin, and join her for the stew.
x=(player action/dialogue choice)
x cop feel
h-scene starts
x Trying to make you feel good
x I'm sorry
x I understand
After seeing Rilke at her son's grave, you have to wait for the next event trigger/leave castle and come back.
x I have to admit something
x I'm sorry Rilke
x I understand if you want me to leave
x You did what you could Rilke
x What happened?
x I'm so sorry
x I think I can manage that
h-scene
x Glad I could make you feel better
Leave cabin, wait for new event trigger/leave castle, comeback to cabin.
x I've been thinking about you a lot too
x sounds good to me!
h-scene
x I really enjoyed that
Hope that helps. Also you can search in the thread, with the search bar, for more Rilke information. We've had other discussions about Rilke's scenes before. That way you wouldn't have to wait for an answer.
I always bind her. That way you don't actually have to change your morality to have her as a companion. Even if you're a "good" character. Xyless is the spirit of domination so if she is binded to the player she'll like a dominant and a sadist player. So she likes being degraded. Even if she doesn't openly admit it at first. If she is free, and good or evil morality for player, her end cards will always reflect her trying to take over the world or succeed Ginsohn. Then she will eventually vanish from the player. If she is binded she'll actually warm up to a good player, and be impressed by an evil player. Without leaving them, even with her amulet gone from her companion quest. Also you can't marry her in game. Which I always found an interesting choice since you get the possible future vision with her. It never actually happens in game. That's my opinion on the matter.