I would like to share a workbook with multiple worksheets by only two users, simultaneously.
I would like to allow the contained Code and Macros to be enabled and work within the shared workbook.
SIDE NOTE: These two users sit side-by-side at a dispatch center desk.

I would also like to allow multiple users(6-9) use of the workbook in a "Read Only" capacity.
Of course, I want to ensure that the shared workbook structure is protected so that only I can edit the Workbook should structure changes be required.
Three levels of user levels - "Read Only, Edit, Administrator."

Understanding the risks and issues of a shared workbook are their suggestions or opinions concerning this issues?

Respectfully? Coop