Yes of course! Both German and English is fine.
No, we can work together online. For some formats such like the Kick-Off Workshop or Final Pitch, participation (min. 1 team member) is mandatory.
Yes, of course. However, we recommend working in teams as soon as possible. Together we accomplish more.
The main impact of the project (i.e. the implementation) needs to happen in Austria. It is not a problem if you or your team members are not Austrian citizens.