How can one password protect all pages in a INDD document except for a few pages (front and last page open for editing without password).
I would appreciate your help.
There is no mechanism for password protection of any sort on InDesign files. Break the document into multiple files and send only those that the recipient should edit.
You can't apply password protection to an InDesign file using InDesign.
What workflow are you attempting to create? InDesign files are intended for one person to work on at a time, they are not shared files.
Once you've created output like PDF or EPUB then protection is possible. But if you're using a print workflow, you would definitely not want to password protect a PDF you're sending to your printer.