I've seen suggestions of behavioral problems with Charisma in the past, but I've never seen anyone who actually knew what they were talking about. It all seemed like people making wild guesses based on the fact that she was fired. If you have a more legit version of that story, I'd be really interested in seeing it.
However, the story from Charisma is that she had been dealing with her own personal stuff (there may have been more than one miscarriage) which probably contributed to the stress, but Joss actually got mad at her when she revealed that she was pregnant, because it ruined his plans for the season. Not only did he fire her... he didn't actually tell her that he fired her. She found out about it in the press, and she found out about it after she'd missed pilot season, which was a sh*tty move on the part of the Angel producers. Especially since they'd been working with her for seven seasons by that point.
So the next year, they asked her to return to the show. She was hesitant, because she didn't want to come back if she was just going to be killed off. They swore that they weren't going to kill her off, and eventually, they talked her into signing. After she signed, they told her that she was going to be killed off.
Charisma tells the story in a joking manner, saying that she actually liked the approach once they told her, but the fact is, they lied to her and manipulated her into coming back.
That story is relevant to me because it reminds me of what they did with Robia LaMorte. After season 2 of Buffy, Robia had a life changing experience where she became a born-again Christian (she is now a minister, so it was a huge deal for her, not some subtle event). She signed on to appear on season 3 of Buffy, believing that she would be playing some form of Jenny Calendar. Instead, she found out (after signing) that she was going to be playing the Buffyverse equivalent of Satan. It was something that she was very uncomfortable with. It was another example of the bait and switch that Joss and his team used, which I find distasteful (it's Hollywood, so I'm not shocked by it. I just think it's in poor taste to sign someone under false pretenses when you know they will be uncomfortable).
To be clear, I don't care if Joss isn't a feminist. I'm not a feminist. I don't like the militant feminists that Joss has always pretended to be, so that's not what bothers me about him. It's the con he pulls with it. He used feminism to sell his work and to turn himself into some sort of feminist icon, and I have always found it frustrating because I've always seen right through it. I've always seen the "hot girl on girl" vibe in his work while other people were going on about "empowering lesbian relationships". I've always seen the flaw in his presenting his work as feminist, while depicting abuse toward women in a strangely positive light. Buffy went from one very abusive relationship to the next, and it was played as romance. Echo was a mindless sex slave who didn't even develop a personality until somewhere in season 2 (by which point they were just falling back on old apocalypse stories on Dollhouse, because they had no original stories to play). Cordelia was impregnated by demons something like three times on Angel! And in one early idea for Firefly, Joss wanted to show us a syringe that Inara kept on hand in case of an attack. Essentially, she would inject herself and whoever sexually assaulted her would die. In the early episode pitch, Joss suggested that Inara would be captured by reavers and taken to their ship. When Mal found her, every reaver on the ship would be dead, suggesting that they had all raped Inara... and only at this point would Mal begin to treat Inara as a woman, rather than a whore.
Again, I'm not saying that it's not valid to put women through crap in stories. I'm just saying that it always seemed strange to me that Joss was going on about being a feminist activist while telling these stories. The feminist angle was BS from the start. Anyone who reads his tweets will see him comparing women to dogs, or criticizing the appearance of teenage girls who survived cancer (!!!!!). So when he gets jobs like Batgirl because of his feminist street creds, I get annoyed. Not even because the feminist stuff is an act, but because Joss hasn't produced anything worthwhile since Firefly was on TV. His Avengers movies are crap. Dollhouse was crap. Most of Angel was crap. Even Serenity fell far, far below the level of writing found on the Firefly series. Joss has taken to fluffing his ego rather than telling stories, as I've been saying for years.
I don't really care about Justice League. I think people are probably blowing his role as stand-in director way out of proportion. What he's filming was probably approved of and planned by Snyder before he left (which is probably why he was working with Joss in the first place), and it's actually not that unusual for someone else to direct bits and pieces of movies that are officially directed by someone else. I think the media is running with it because it feeds into the narrative of the DCEU being a flop, but in reality, it's just someone filling in after something truly horrible happened. And if the rumors are true that Joss is taking this opportunity to change the tone and purpose of the movie without Snyder's blessing, it just confirms that he is a douchebag on a truly massive level. And we will be able to tell, because Joss' writing style is pretty distinctive (meaning that he doesn't really write different characters and styles. They all just talk like Joss). We'll have to comment on Justice League after we see it and know how it turns out.
Batgirl is a different story. He got that job for one reason, and he doesn't deserve it. He was never the best choice for that job, and Kai Cole's essay just highlights that point.