Restrict a User from Modifying a Document Opened by Another User for Modifications
Use the Check-in Check-out feature to a document so that its not available to others.
 

Restrict Users from Viewing Files Outside Globodox
Encrypt document to restrict users to open documents outside Globodox.

Restrict Users from Viewing Certain Documents
Set permission to the document as to who can view the document.

Keep a Record of the Actions of all Globodox Users
Create logs of every action that is carried out on the document.