Disable gallery support

I’m writing a gallery-plugin, where the user can select to use this plugin instead of wordpress own gallery function.
That is, if this option is selected, the gallerystring will be “[gallery …..” and look pretty much the same as the original gallery string, and it will override the gallery_shortcode() in media.php and stuff.

The problem I’m having, how ever, is that the user now still can click this gallery and make changes. That’s not what i want in this case.
I have googled and found some stuff that does not work, the only thing i found was a js that removed this values when hitting “add media”, but the user can still click on the gallery in the editor and hit the button to change it. How can i stop the user from doing this?
I’ve tried the ugly hacks by hiding this button with css and “add_editor_styles”, but i can’t even get that to work. Any suggestions?