Here are some findings from my first trials:
Custom style sheet
Does it makes sense to add CSS for each instance. This option should be hidden by default on courses or a administrator permission by default.
It makes no sense to send notifications to Authentificated users of site in courses. This should be disabled as selection
Radio button question type
Make the user experience more intuitive. The user expects to add the options direct after the question. So the question text and the option text area should be directly together. In the moment the mandatory options field is not visible from the beginning in the form. All mandatory fields should be visible if the question is edited
A picture added to a question text in radio button question type is not visible in preview mode, but in question overview (itemsmanage.php)
In preview mode the question text and the first option should be on the same line. (question position left) Actually question text starts some px lower.
Reduce size of the warning message: You are in preview mode: buttons for data saving are not supposed to display
If I mark a question in preview mode data saving is disabled. If a question is marked and I will leave the page, system warns me that data may not be saved. This should be disabled because its not possible to save the data in preview mode.
The Survey summary page includes functionalities (report section, user template section and master template section) that should be in the settings area only. Actualy they are in both areas. My suggestion: delete them in the page.
I've tried to find the survey report and found it accidentially. Why didn't you add it to the horizontal navigation after Responses as direct link to 'frequency distribution'? This will be the most often used link by teachers.
Is it possible to give students access to survey results? I didn't found a permission to allow access to survey result.
Can you add an overviewreport showing the attempts for all questions in one page? The graphical presentation of the question looks very similar to the old survey module and is very big. The feedback module uses a much better visualization.