Can individual columns be password protected for separate people, so that others can view information, but only change data in their column?
Yes. You need to be connected to an Active Directory domain. Then you can select a range and go Review > Allow Users to Edit Ranges.
Click the New button and set a password
Click the Permissions button and then add users or groups from your domain address book
As with all other cell protection, this only applies after the sheet is protected.