For context, I answered this after your edit. First, I don't know how to add another context menu on a file manager, but I imagine if there is a way to do that, there is a command to be run when doing it. Hence, what I will answer is only the command.
For editing a file, you absolutely don't need to open the editor as root. You can however, make a temporary copy of a file that your own user has access to, edit those temporary files, and when you are done editing it just replace the old file. This is what sudoedit FILE does.
Secondly, for manipulating a file, I agree with the other commenter that it still is a bad practice to run the file manager as root. Instead, try to add a context menu for taking ownership of a file/folder recursively. chown does exactly that. Of course chown won't save you if that file is a network mount with some form of other access control.
Third and last, yes I agree that if a user wanted to nuke their installation it is their right to do so. However, do remember that this is also a forum and that we always remind each other the best practice since maybe another user will stumble upon this and think "oh, this is how it is in Linux". We do not have the equivalent of "Run as Administrator" here in linux as that would mess up a lot of assumptions for other programs and easily make the system unstable or outright unusable.