Hello!
I dont know of any preference file that can do what you requested but you can try the following...
Download
QuickConvert.
Go to ~/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/Resources/HIToolbox.rsrc and make two backup copies of this file.
Drag one of the backup copies onto QuickConvert, the app will launch and nothing will happen.
Launch Iconographer and open up the copy that you dropped on QuickConvert.
Scroll a third of the way down the dialog until you find icon number -20789.
Double click on this icon and delete the mask (the black and white version of the icon) and the icon (the color version) but do not delete the whole family.
Save the file and quit Iconographer.
Drag the file onto the QuickConvert icon again, again nothing happens. Now quit all open apps except for the Finder.
Replace the original HIToolbox.rsrc with the edited one and restart the computer.
Now, since the finder cannot find the data for the alias badge, it should not display it. Also, make sure you keep the original file in a safe location just in case something happens that you need to revert to the original settings.
Hope this helps!
Albert