I have activated master password but it keeps on asking it every time it starts up. my homepage is about:blank and even with BOTH plugins and add-ons DISABLED, it still asks for the master password. Is this normal behavior?
Yes always that you start the Firefox it will ask the password, but it ask always that you open a new tab is a issue or other window.
If you cancel the request, does it quickly recur, or not until you reach a site you've actually saved a password for?
I am not a big believer in saving passwords in Firefox; I have the setting to save passwords turned off. So my experience is limited to having saved passwords for FireFTP logins.
I am not prompted to enter my Master Password unless/until I open one of the following:
So at least with my settings, I would be surprised to get a prompt when opening Firefox.
Other things that need your attention:
Your System Details List shows that you have a user.js file in the profile folder to initialize some prefs each time you start Firefox.
The user.js file is only present if you or other software has created it, so normally it wouldn't be there. You can check its content with a plain text editor if you didn't create this file yourself.
The user.js file is read each time you start Firefox and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.
What is the home page setting or what pages open when you start Firefox?
You can check for problems with the sessionstore.js and sessionstore.bak files in the Firefox profile folder that store session data.
Rename (or delete) the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox profile folder.
Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost and you will have to recreate them (make a note or bookmark them if possible).