Hello, welcome to Feng Office Forums.
There are one way syncs provided.. In order to see the calendar one you need to go to Administration>General, and allow the option 'Show feed links'. Then you need to go to the Calendar tab and look for a button at your right -above Saturday column in the Week view-
For the time being, regarding the contacts sync you can import/export them anywhere (one way sync), but not doing a full synchronization.
About full synchronizations, right now we do not have such features, but if you happen to get someone to develop them or if you would like to help sponsoring them (you may do this contacting sales@fengoffice.com), we would be happy to add them in our next release.
Best regards,
Francisco