i had a hard time with those too lol... there's a guide to how to get each ending in the artbook if you can afford throwing 5 bucks at the devs!
if not, i'm not sure what would be good advice for getting ending 2, but i think getting ending 8 takes a delicate balance of having cassidy believe the best of elowen/not dwell too much on her ~true nature~ while Also not completely giving up faith in alexander. at the "what's cassidy's final impression of elowen" choice i had all 4 options which had never happened before in my other playthroughs.