1) Yes, VTK and spry can be used. Do you have a sample page where you tried adding spry and it didn't work? I could try to debug that.
2) They can be.
3) If you use the dynamic button of the checkbox it will have an option for checking. Usually the value would be the course number, not the validated field value. The validated field value should be used for the dynamic value to check the box associated with that value. So it looks like your checkbox is set up wrong. Update the value to be the course number and use the dynamic button in the properties panel to select the previously validated value.