Hi,
Thanks for using the Facebook Importer. I can help answer your questions.
I am wondering if there is a way that I can link two calendars from two different sites? This way I could have my main site displaying all my events from different projekts and on the projekt pages their own calendar.
Unfortunately, there is no feature to link calendars from different sites. It could be possible with RSS feeds or event the WordPress Rest API, but that can only be done by customization, which we cannot support.
If you would like to request that feature please head to our UserVoice Page and add your own or upvote that feature as they will increase the chances of it being added to a future version.
http://tribe.uservoice.com/forums/195723-feature-ideas
Cheers