As I have already pointed out earlier in the thread most, if not all, of the features that you want already exist in Mosaic. I can only assume that you are less familiar with how to use it then you may need to be.
However, admittedly, I may be mistaken on the “file viewing” issue as I think I would like some further clarification of exactly what you want.
Every so often I respond on how to do things in Mosaic. Really this indicates that the online instructions are inadequate. They do not appear to be updated as versions go by. @Phil please note: