It is not ethical. Hinata Hyuuga is a character, and creating fanfiction that involves abuse goes against the spirit of respecting the character and can also be disturbing to other fans who love the character for her positive traits.
Love and relationship are very common. Since they are a popular couple in the Naruto series, many fanfictions explore how their relationship develops further, like their married life or how they deal with challenges as a couple.
You can try fanfiction websites like FanFiction.net or Archive of Our Own. They have a large collection of fanfictions on various topics, including those about Naruto and Hinata.
They would probably be very proud. Despite their differences, both Hinata and Neji are highly skilled members of the Hyuuga clan. For the clan, watching them fight in the fanfiction would be like seeing the best of their combat techniques and kekkei genkai on display. They might also be analyzing their moves to see how they can further improve the clan's fighting style.
Well, the Hyuuga clan has certain expectations and standards. Their presence during the Hinata vs Neji fight in the fanfiction would make both fighters more conscious of these. Hinata, who has always been in Neji's shadow in the eyes of some in the clan, would be trying extra hard to show that she can be a great Hyuuga. Neji, who has always been seen as a strong representative of the clan's old ways, would be fighting not just to win against Hinata but also to maintain his status among the clan. Their fight is thus shaped by the clan's overarching influence.
Sexy Hinata hentai comics can vary greatly. Some might emphasize her emotional connection in a sexual context, while others might just focus on the visual aspect. But keep in mind that this kind of content can be controversial and might not be in line with mainstream values.
The main characters are obviously Naruto and Hinata. Naruto is a very energetic and determined ninja who has always strived to be recognized. Hinata is a shy yet strong - willed kunoichi with a deep love for Naruto.
One possible plotline could be Naruto and Hinata going on an adventure together outside of the Hidden Leaf Village. They might face some new and unexpected enemies and have to rely on each other's skills to survive.
I'm not sure if it's popular. It depends on various factors like how well it's written, how it's promoted within the fan community, and the size of the Hyuuga fandom interested in Sakura -centric stories.