Regarding the whole "turns into a Stalfos" thing, it is highly unlikely, first, it just doesn't seem right, second, the HS calls link his child, sugggesting a family line, which would mean he
did return from lost woods (imb4 he went back to the forest), third and last, many people are saying he became a Stalfos but in official artworks and in-game screenhots it can be clearly seen he is shade, not a Stalfos

Also, regarding the earthquake, saying there were two earthquakes would be adjusting evidence to fit the theory, I still think there was an earthquake, but the landslides I think were recent (Zant's fault maybe?)
Edit: Images are better
here and
here