Manage the Rekordbox database

Hi, I would like to share my experience with you to find a better way to manage a "common" database

II've got to Mac, a recent Mac Mini with Mavericks and a White 13" MacBook (2007 + OS 10.6.8 Snow Leopard). Since my hard disc fail on my MacBook, I decided to put my collection on a USB Key. I mean, each trax are on the USB Key. I connect my key on the Mac Mini, work on the collection and playlist, and I load new track after (analyze with MIK) from iTunes collection. But I play with DJ AERO using whether the USB Key, wheter the MacBook.

I read that the most important files are : embdatabase (?)+ settings (containing the bank repairs); is there a "good" way to "synchronyze" the 2 databases (I've changed hard disc on MacBook with a SSD Drive and all the trax are on) ?

And last, where are the database files and setting files on Maverick + I confirm that everything works fine !!!

Thank you for your help and have a nice day :-)