no problem buddy
the mesh quality is very good, there are some bumps/scars where the shiny surface of the apple was reflecting the light, but that's normal. overall the mesh is quite detailed and regular. the texture is also quite detailed.
yes, you can still fit the camera inside the case waterproof case, not sure if it's a good idea to fly your drone underwater though
i haven't had the chance to benchmark it against another camera unfortunately.
the lens job is a bit fiddly and you need time and slow hands, but is achievable by following any youtube video explaining it. after the lens swap you can still put the stock one back on for the fisheye effect.