No, it is not appropriate. Such content often involves inappropriate and unethical themes. It objectifies and sexualizes lesbians in a way that is disrespectful and goes against basic values of equality and respect in society.
It's a complex issue. From a legal perspective in many places, any form of non - consensual sexual punishment is illegal and unethical. But in the world of adult sexual exploration like in some BDSM communities where there are strict rules and communication, it can be seen as ethical as long as boundaries are respected. For example, they have safe words and agreements in place.
No. Castration is a form of extreme and cruel punishment that violates basic human rights. Using it in sex stories is not only unethical but also disturbing. It promotes violence and inhumane treatment in a sexual context which is completely unacceptable in a civilized society.
There could also be a story where a daddy punishes his younger self in a memory. For example, he might remember the time when he didn't listen to his parents and got in trouble at school. He uses this memory as a reminder to be strict with his own kids in a proper way.
There are many positive and healthy literary genres to choose from. For example, adventure stories like 'Treasure Island' which take you on exciting voyages filled with pirates and hidden treasures. Another option is mystery novels such as those by Agatha Christie, where you can try to solve the mystery along with the detective. Also, science - fiction works like '1984' offer thought - provoking views on society and the future.
Even in more liberal regions, there are still limits and regulations. These stories are not in line with the general social values of promoting a healthy and positive social environment, so they are usually restricted.