Most darkfriends are really in it for themselves, expecting the Dark One to reward them for their service, rather than wanting to free the Dark One for its own sake. Most of them have not realized that if the DO actually wins they will be collateral damage in the destruction of the entire world. Thus, the DO may want balefire used without restraint but most of his followers would not be willing to use it to the required extent. If he pushes for it he might get a mass darkfriend revolt instead, and he's smart enough to realize this. Ishamael would go along with balefiring the Pattern to tatters, but he's just one person. He might be able to pull it off with the Choedan Kal, but with anything short of that he'd face a universal mutiny before reaching the point of no return.
The DO may or may not want the world torn apart by excessive balefire use. I don't think there is enough evidence to decide this either way yet.
I'm going to have to respectfully disagree with you on this one. Some of the most powerful people ever, the Forsaken, do whatever he tells them. If he told them to balefire the world into oblivion they most definately would obey. As would any Forsaken underlings. The DO rules out of fear as do the Forsaken over their cronies. If anyone disobeys they are simply killed off. That goes all the way down the chain of command on the side of the shadow. I don't see any type of revolt taking place. Furthermore, the Darkfriends that matter in this discussion are Aes Sedai Black Ajah and any rogue Ashaman that have crossed over. All of the Black Ajah are fully aware of what the DO represents. It's not just some shmuck darkfriends that would come into play in this theory only the channelers.
So, I still believe that if the DO intended the world be ended by excessive balefire use then that would have, at the very least, already have been attempted.