which is perfectly normal in multiplayer since punkbuster verifies the integrity of files to prevent cheating and since TH in COD4 uses a hack ...
WSF does not modify any files, so there's nothing to verify. WSF modifies a specific part of memory, which can actually be changed by the user in a valid manner. Because the user can change this on his own, PB does not scan this value. That's why I can modify it beyond bounds and not have a problem.
so no it's not possible, unless you find an undetectable hack but in this case one could probably use this to program another cheating program which means sooner or later the undetectable hack would be detected again ...
This depends. It's not possible with mine because I do not hook Direct3D or other parts of the game. Because there is no hooking going on, there's really nothing to exploit in my own code. Applications that do hook Direct3D in games (like Fraps or Xfire) can be, and have been, hacked.