A crossover with Moana might be interesting too. Moana could take Elsa and Anna on a journey across the ocean in her boat. Elsa could use her ice powers to create paths or structures on the water. They could face challenges like sea monsters and learn from each other's different ways of life.
I think in 'Marvel The Flash Crossover Fanfiction', the most interesting part would be how the Flash's abilities are perceived in the Marvel universe. Since the power scales and the overall feel of the two universes are different. Maybe the Flash would be seen as an anomaly, or perhaps a new kind of hero that the Marvel characters have to adapt to. It could also explore how the Flash's speed affects time and space in a world that already has characters like Doctor Strange who are well - versed in such concepts.
Sure does. Disney's purchase of Marvel Comics back in 2009 gave them control over a vast universe of superheroes and related properties. This has led to numerous cross-platform projects and expanded the reach of the Marvel brand.
Yes. When Disney bought Marvel, they took on the responsibility of making Marvel Comics. They have the resources and reach to keep the comic universe expanding and engaging for fans.