ok, So is it safe to say we can have StudentEx_, SchoolsEx and TeacherIdentityEx views? And perhaps SchoolSurveyEx, TeacherSurveyEx and StudentEnrolmentEx for any new field that could change over time?

Yes - two points

1) you'd probably make the columns a union of any column that may appear in any workbook FSM, RMI etc etc. If the column is not present, it's just null.

in other words, I don't think we want to be maintaining custom version of this TeacherSurveyEx, SchoolSurveyEx views by country.

2) Although as per my sample above its straightforward to enumerate all the columns in the Xml field (across all records) you may think that you could use this to build a generic Xml that responded to whatever it found in the data.

But the Xml requires a literals : e.g. r.value('@Language') cannot be r.value(columnnamevariable)