Angel Island pretty much dosen't even matter, hell in SA1 it didn't even hold the master emerald (unless I missed a huge plot point).
no, you didn't
it became a useless plot device after chaos emeralds suddenly became the thing that does everything
consider the time between games
you're like my dad when he watches shows; he interprets scene changes as immediate changes in events and leaves no room to assume there'd be anything in between.
read above, it just became a useless plot device when chaos emeralds suddenly gained 500 powers