Another theme is time - related. Since Homura has the ability to manipulate time in the show, many fanfictions play with this concept in relation to her relationship with Madoka. For example, stories might involve Homura going back in time to save Madoka in different ways or dealing with the consequences of her time - traveling on their relationship.
Well, the 'madoka visual novel' could be an immersive experience that dives into the world of Madoka. It may include elements like the battles against witches, the internal struggles of the magical girls, and the overall dark and complex themes of the Madoka universe.
I think there are several, but the exact number might change as new ones could be released. You might want to check reliable manga databases or official sources for the most accurate count.
You can try fanfiction websites like Archive of Our Own (AO3). Just search for 'Homura x Madoka' in the Madoka Magica section. There are usually a lot of great works there, with different storylines and writing styles.
Yes, there are. You can find them on some popular fanfiction websites. Just search for 'Gingka and Madoka love fanfiction' and you'll likely come across some interesting stories.
It depends. While the 'Puella Magi Madoka Magica' series has a lot of complex and sometimes dark themes, if the visual novel follows the general storyline, it might not be suitable for very young children.