From my knowledge and experience I can say a few thoughts:
1) Nowadays even in developed countries there are gangster groups that kidnap and sell people (just information from the news) and it is disgusting and one of my dreams is that this would not happen.
2) Based on my experience getting Stockholm syndrome or mental withdrawal from blackmail is not possible as it's more of a hentai plot than something you can get in real life. Since usually all these events are based on beating and creating fear. And it depends on a lot of circumstances how you deal with it. But the worst thing that can happen is to put up with the situation, where you just tolerate it and take it as just an inconvenient boss.
3) I know a lot of girls like hardcore sex and fantasise about being raped. Although I love that kind of thing myself too. And from experience I can tell you a few things.
3.1 You can with your boyfriend or find a man who will agree to conduct an unusual bdsm session in the format of kidnapping or rape. And just talk in advance about the approximate scenario and set the boundaries of allowed and forbidden. (Without taboos, a fun game can turn into hell, as people are violent by nature)
3.2 I would not recommend theatrical kidnapping in public places, as an unexpected witness may call the police.
3.3 I would not recommend looking for people to play these games among strangers on the Internet. I would recommend to choose people for such a game among familiar Masters or with Masters with whom you have already held sessions.
3.4 In my opinion the blackmail format is a bad option. Because any intimate recording could end up on the internet. And I've seen a lot of stories about ex-boyfriends or ex-husbands posting this material in retaliation or just hacking into people's accounts and leaking intimate photos. And not only can it do psychological trauma, but it can create problems in the professional sphere.