No. 'Pokemon midriff fanfic' doesn't sound like something that would be appropriate for all ages. The very idea of focusing on such a specific and somewhat odd part of a Pokemon's body in a fanfic context could lead to content that might be confusing or inappropriate for children. Pokemon is generally family - friendly, but this kind of fanfic seems to deviate from that norm.
Most likely not. Given that it's a rather strange and non - traditional concept focusing on a Pokemon's midriff, it may contain elements that are not suitable for younger audiences. Fanfics can vary widely in their content, and this one sounds like it could potentially have content that is more appropriate for older or more mature Pokemon fans.
It's doubtful that 'pokemon midriff fanfic' is appropriate for all ages. While Pokemon as a whole has a broad appeal across different age groups, this specific type of fanfic seems to be a more niche and potentially edgy creation. It could potentially include content that is not in line with the typical family - friendly nature of the Pokemon franchise, so it's probably better suited for a more mature or older audience within the fan community.