Often, there's a theme of self - discovery. As Female Zim is a different take on the character, she might be on a journey to figure out who she is in this new form. Also, the theme of adaptation is common. Just like in the original where Zim has to adapt to Earth, Female Zim may have her own unique ways of adapting, whether it's to Earth's environment or to the reactions of the other characters around her. And there's also the theme of power. How does being female change Zim's perception and use of power? This is something that many fanfictions like to play with.
A really interesting 'Invader Zim female Zim fanfiction' is 'Zim as a Girl: The Alter Ego'. This story plays around with the idea of Zim having a female alter ego. It's fascinating to see how the other characters react to this new version of Zim. Additionally, 'Female Zim in the Human World' is a great read. It focuses on how Female Zim adapts to human society, with some really funny moments like her trying to understand human fashion and social norms.
It depends on how you look at it. Some fans consider the comics canon because they continue and enrich the storylines from the show. However, others might have reservations based on personal interpretations.
You can start by finding a collection or anthology of Invader Zim comics. Many bookstores or online platforms sell them. Then, just open the book and start from the first page.
Well, it's a bit hard to give an exact number. Different publishers and creators have come up with various Invader Zim comic offerings over the years. You might have to do some research to get a precise count.
There are various new 2019 Invader Zim fanfiction stories. Some might focus on new adventures of Zim and Dib on Earth. For example, there could be a story where Zim discovers a new way to try and take over the Earth that involves some strange new technology he's created. Another might be about Dib finally getting proof of Zim's alien nature in a really unexpected way.