Hakeem, you can't disable copying. That form of DRM doesn't work. It fails badly, since someone else will make a problem that CAN save it (or hack the WE directly). It can't be done in a manner that cannot be circumvented.
If the game can play it, it can be circumvented. Programs can be made regardless of what means of protection or locking are used.
No matter who you are, your map is not so important that it needs to be protected from the eyes of other modders. I can understand wanting noobs not to add cheats or try to take your credit, but preventing copying would stop most of them.
If you've done something in your map that I don't know how to do, I might want to see how you did it and learn something. Disabling copying and pasting for locked maps allows me to see how it works. A noob on the other hand, would only want to change strings or add cheat triggers, with no intent on learning.
I know that Vex's optimiser can be deprotected, but the JASS code is insanely hard to maintain or improve.
"maintain or improve" is not what you are trying to stop with locked maps. You're trying to stop noobs from stealing or cheating your map, neither of which classify as maintaining or improvement. Modders on the other hand might want to do just that.
Protection and locking don't protect you as the author. The only way to do that is to tell people you are the author. Like uploading your map to a site such as this.
If they want to be really revolutionary with Starcraft II, then they could have an author system built into Battle.net. If someone hosts a map with a name matching your map, and it's been edited, then they can get banned. It's probably not a perfect system, but it would require some serious dedication (and programming skills) to get around it.