Refering to your questions above:
Example classlist at http://webwork.maa.org/wiki/Classlist_Files. In your csv file(s), just make sure to enter the proper section for students in the proper column.
2) Instructors in the course will be able to see grades for all students.
3) Under "Course Configuration", select "E-Mail" and set "Feedback by Section" to true. By default, email is sent to everyone with TA or higher permission (you can change that). Just make sure in the classlist displayed on the web that TA's and/or instructors are assigned to their own section.
Hope this helps,
Arnie