Am I the only one with ab bad feeling about making Odoo directly accessible from the Internet?

Is there a way to only sync selected data between to Odoo installation.

Main data is on our server. only accessible with VPN

And a sync-tool that synchronizes only lets say:

- User data for the frontend

- selected User documents (orders, invoices, offers etc..)

- eLearning

- Webshop

- etc...