There are quite a few benefits. For starters, a guy roommate can offer a different perspective on things like decorating the room or handling household problems. He might be more practical in some ways. Also, having a male around can provide a sense of security, especially if the area is not very safe. Moreover, it can help in expanding social circles as the guy may introduce his friends and vice versa.
One challenge could be privacy. For example, a girl might feel uncomfortable changing clothes in common areas. Also, there could be differences in cleaning habits. Guys are sometimes messier. And there might be misunderstandings about sharing expenses evenly.
One positive experience could be that they can offer unique perspectives to each other. Since they may have faced similar challenges in society due to their sexual orientation, they can support and understand each other better. For instance, if one is facing discrimination at work, the other can provide both emotional support and practical advice on how to deal with it.
One great 'Draco and Hermione as Roommates' fanfic is 'Unexpected Bonds'. In it, their initial animosity slowly turns into friendship and then something more. The author does a great job of showing how they adapt to living together and gradually see each other in a new light. Another one to check out is 'Roommate Arrangements'. It focuses on the comical situations that arise from their very different personalities sharing a living space.
I'm sorry, but I don't actually know the specific 'the perfect roommates' full story. You could try looking for it in a book, a relevant website, or asking someone who might have read or heard it.
The main points of a roommates agreement in a manhwa could be responsibilities for grocery shopping, rules for borrowing each other's stuff, and maybe even agreements on pet care if applicable.
A good fanfic of this kind needs to have a believable relationship development. Since they are such different characters in the original series, the writer has to show how they can gradually become friends or more. It should also have some unique elements. Maybe they discover a secret room in Hogwarts while living together or they have to team up to solve a mystery that only they can solve because of their combined knowledge.
Another theme might be cooperation. They have to cooperate to keep the living space clean, pay the bills on time, and deal with any issues that come up in the shared living situation. For example, if there is a problem with the plumbing, they need to work together to get it fixed. Also, there could be a theme of personal growth. Living with others can teach you a lot about yourself and how to get along with different types of people. Maybe one roommate was shy at first but became more outgoing because of the positive influence of the others.
Sharing inappropriate stories about roommates is unethical and disrespectful to others' privacy. We should focus on positive and respectful aspects of roommate relationships, like sharing good memories of having movie nights or helping each other with studies.