Have you tried simply checking the Cannot be Blank option for the field or using a Validation rule that requires the field contain information?
Using a validation rule is helpful when the field doesn't always require information, e.g. if that part of the form isn't displayed because check box X wasn't checked. If you are not validating based on a checkbox, etc and you just want that field to have content, just try the Cannnot be Blank option in the field properties.
For the rule, add a new Validation Rule to the RequiredField
Condition is:
CheckBoxX = TRUE and
RequiredField is blank
You can add a screen tip and a dialog box to the rule too.
I haven't needed to do any view switching, but I assume everything would work the same. Good Luck.