Best Practice for re-using API Data in WordPress?

Use Transients API – http://codex.wordpress.org/Transients_API

I would also suggest you to use WordPress HTTP API – http://codex.wordpress.org/HTTP_API instead of file_get_contents

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)