Seems well thought through, but the concept of putting a general-purpose file system on an embedded microcontroller is a common mistake. These are single-purpose systems, you don't need to use filenames and have POSIX semantics, you typically just need to put your data into a circular buffer on FLASH. The circular buffer (with checksummed elements) will take care of bad-block management and wear levelling for you. I'…
i have the exact opposite opinion. such circular buffers only suit limited file system activities, such as logs. if you want editable config files of varying lengths, you need a real fs. i'll concede that features like directory structures and timestamps can be omitted though.