In the Virtual Console on 3ds you can follow the steps outlined in this video by Austin John Plays to obtain a shiny mew that can be transferred to S/V via pokemon home- i have done this and now offering the PK9 file for you all, it is untouched.
transferred on 28th of Sept 2023 after pokemon home updates.
I don't know, probably because your emulator uses a big save?
You haphazardly changed the extension from .smr to .sav.
I'm unsure if you load back a .sav sized file to the emulator, whether would it work
You may have to untrim the .sav after editing.
Better learn how to use Hex editor to trim and untrim