It's just an expansion of their mandate happens all the time. Instead of creating a whole new department just to regulate launches adding it to the department that will be issuing a license anyways (anything worth putting up is going to be transmitting down so pretty much any launch will have the FCC looking at it already).
As for the rest it's really hard to do much of anything covertly in space, if it's above the size of a softball the DoD will pick it up on it's space monitoring sensors. Same thing with changing orbits unannounced they'll know within at most an orbit when the object suddenly is not where they expect it to be.
In the end the answer is could you? Yes, theoretically. But you'd have to find a launch company willing to host you and prey you have somewhere good to hide/a host strong enough to protect you because you're going to piss off every single country with a space program.