different child fields based on parent record settings

I have a client who wants to convert their student rosters to online. I'm trying to do this without an extreme number of tables or table views.
three tables - tbl_roster, tbl_class_type, tbl_students
instructor creates a roster in tbl_roster. There is an option in there to select which class type - this dropdown is populated from tbl_class_type.
tbl_students has the following fields - id, firstname, lastname, pass/fail, elearning, level2, level3
tbl_class_type has ID, class_name
Example data for class_type would be

1 bicycle

2 cooking

3 coding
= HERE IS WHERE IT GETS TRICKY =
if the roster is for class (1) bicycle then students added to that roster as child records only need to have id, firstname, lastname, pass/fail.
if the roster is for class (2) cooking then students added to that roster as child records need to have id, firstname, lastname, pass/fail, level2, level3
if the roster is for class (3) coding then students added to that roster as child records need to have id, firstname, lastname, pass/fail, elearning, level2, level3
So, I'm basically trying to hide fields on the student add/edit form if the parent is a certain class.
If I can't figure a way to do this with logic then the messy option is to create a different roster_view for every class and a different student_view for every class. So, I would end up with 12 views of the roster table, 12 views of the student table. I don't want to go that route because if they want to change something simple on the student form (like capture middle name) then I have to update all those views.