Google App Engine + Google Cloud Storage + Sqlite3 + Django/Python
Google Cloud SQL is meant for this, why don't you want to use it?
If you have every frontend instance load the DB file, you'll have a really hard time synchronizing them.  It just doesn't make sense.  Why would you want to do this?
since it is not possible to access mysql remotely on GAE, without the google cloud sql, 
could I put a sqlite3 file on google cloud storage and access it through the GAE with django.db.backends.sqlite3?
Thanks.