That trem post looks like the issue with the original JEM555's. Mine was sent back for repairs 3 times under warranty because the soft basswood actually broke and split.
When the guitar played properly I fell in love with it. After the warranty was done I finally took it to a reputable luthier (wasn't into doing it myself back then) and they routed out the basswood, dropped in an ebony block and remounted the trem. It's been rock solid ever since.
Ebony might now be what you're looking for on a white guitar but maybe a good chunk of maple and some paint??
BigM555