I've completed about 1000 in game days total, I've probably seen everything.
The "witch" is just the elves storyline, which you've already accessed. You get the one elf for breeding and you can make different color/style combinations from that. They have no further storyline for now.
Cece's story is only accessible in the early game it seems. Walk into town at night and call her over when prompted. Then you'll need to talk to her.
Talia's story is very short rn. Ask Poe the blacksmith what's bothering him.
Eros only has a few CGs accessed by playing Blackjack with her and Cece in Cece's storyline.
Church and clothing store lady have no apparent story yet. Flirting with them yields nothing. Mostly ignore for now.
This game is relatively young right now. Give it time and it'll definitely improve. We're already miles beyond where we started.