Thanks for the feedback.
1. I have just updated the text on the login page, as suggested to ‘screen name’. Login with the email is not supported by OSQA.
2. There is a question mark on the upper right corner of the question/answer text field. It links to the markdown syntax.
Basically our Q&A software is based on OSQA. There is no further development on the project. So in my opinion we could/should think about a replacement and send the OSQA to its deserved retirement – maybe next year... ;-)