When you are writing a story that involves your character hitting "rock bottom", can you drop them too far? How much can you take away from them before a recovery is unbelievable?
I think it would depend on your character. Everyone has a different breaking point. I've had characters hit rock bottom mentally/emotionally. In a former story I abandoned, my MC was very naive and something horrible happened that basically made her question everything she had ever thought she'd known. I abandoned the story because I ended up hating her and couldn't stand writing about her anymore. It got to the point where her having a turnaround had just become farfetched and unbelievable... However, in another story, my MC is a lot more resilient. He lost his mentor and best friend but despite it all he's still fighting. As for "too far" I'm not sure. I don't think I'd ever physically mutilate/disfigure any of my characters.
Yeah my MC is going through a situation where the MA has destroyed his entire career, and he has to literally take on a new identity to climb back up to the top. He hides himself under a mask so that can stay under the radar until the time is right to confront the MA.
Depends on your character's personality, but it's good to keep in mind that people are extremely resilient. I've met some people who have been through unspeakable horrors in their lives, one after another, for years, and they still managed to recover, even to be happy. It's a very tough question though, but form experience, everything you thought was just about as much as anyone can handle, double it, no, triple it and put your character through it. Because life is hard and people recover from all kinds of bad situations. That's pretty mild stuff, you can put him through a lot more than that, easily.
Isn't that just another day on Wall Street? It is a bit mild - but then who is the MA to the MC? Office mate? Higher management? Trusted friend? That will make a difference to his 'fall' and recovery.
How far is too far to be believable? It depends on how well you write it, whether you can make the reader believe the character has retained his or her will to fight back.
For me, a character having his arms and legs surgically amputated, his tongue cut out, and his eyelids removed, a la the victims in Darkly Dreaming Dexter by Jeff Lindsay, is too far -- anything less than that is fair game.
I never really thought about that, tbh. As much as I'd throw all sorts of problems on my characters, I don't want to push them past the point where they can't recover, or inflict needless cruelty on them. Also, like Cogito said: It has to make sense with the plot. If I have my character walking down the road and OH MY GOD HIS HOUSE IS ON FIRE with his family trapped in it...and it doesn't pertain at all to the plot, then why do it? Then again, I'm scared of seeing how far I can break my characters because I don't want them to be irrepairably ruined.
Everyone has different breaking points. In what I'm writing I've got two characters that have vastly different breaking points: Daniel's wife dies after Caesarian section to save the child. Daniel never wanted the child, but wound up with it anyways. He can't take the pain of his wife's (one of the 3 people he's ever been able to emotionally connect to) death and contemplates suicide. Eventually he winds up on an epic journey and realizes there is more to live for. Another character, Akatsuki, is double crossed, tortured and raped by the Emperor of his country then held in captivity for 3 years as the Emperor's personal.... *ahem* courtier. His family is killed, and his best friends are tortured, killed, and cannibalized before his eyes, and his blood is drank by a creepy old warrior until he is nearly killed. He lives life to the fullest and keeps trudging forwards. Both are believable (within the story and setting) but it's also very extreme for my latter character. Everyone can bounce back, but some people just /can't/.
If your character starts to resemble Job in the Bible then you've probably gone too far. I don't know anyone real or a character that would last that long before breaking.