[PvK]

Almost.

I think Intercept Messages will simply show you a diplomatic message sent to/from the target, if there happens to be one that turn. Trade details should be available if there are any attached to the intercepted message, but I don't know for sure if they are.

Fake Message sends a fake break treaty or declaration of war message.

Prevent Messages will delete a diplomatic message, if there is one to delete on the turn the mission strikes. This would include a trade message (but it won't affect an existing trade level).

PvK