Well, 'van escaflowne' is a popular anime with a rich universe. 'Rated mm' in the context of fanfiction is a bit unclear, but it could be something unique to the fanfiction community. Fanfiction based on 'van escaflowne' often delves into the characters' emotions and relationships more deeply. It might be that this 'rated mm' fanfiction focuses on a particular relationship type, like a male - male relationship, and explores how the characters from 'van escaflowne' interact in such a relationship. However, without actually reading it, it's hard to be certain.
Sure. One great Naruto Escaflowne fanfiction is 'Naruto in the World of Escaflowne' on FanFiction.net. It combines the unique elements of both Naruto's ninja world and Escaflowne's mecha - filled fantasy world in an interesting way.
You can try looking on some popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including Van escaflowne. Just use the search function and type in 'van escaflowne rated mm' to see if any relevant stories pop up. Another option could be FanFiction.net, although their tagging system might be a bit different, but still worth a try.
Vision and Jarvis are not the same in the comics. Jarvis is often associated with Tony Stark's technology infrastructure, while Vision is a powerful being with its own story arcs and significance.
Vision is not a villain. In the comics, he's usually on the side of justice, using his powers and intelligence for the greater good. His motives and actions are mostly positive.