I already disable Ctrl+C, Ctrl+V, Ctrl+A, Ctrl+Insert, etc.
I know that haven't a perfect way to do this... but i want just turn more difficult to users copy.
I don't know how to do it with the "Select all" at top dropdown menu in Firefox.
Can anybody help me?
I don't think that you're not going to have any luck there.
None of what you have done so far makes anything more difficult to copy since everyone already has a copy of everything in the page before their browser can display it. The only way to make it more difficult to copy is to not put it on the web.
The only affect that what yuo have done so far is that it might drive people away from your site so that you get fewer and fewer visitors over time. Again you can speed that process by removing the page content completely.