Your Class 4 would only be a robot if the internal sensors of the robot could override the human commands. For instance if the human guided it into a furnace, the robot would sense the heat and refuse to proceed. A remote controlled device which was not a robot would go into the furnace and melt.
Maybe class 5 would be a remote controled device, class 4 is a human/AI merging device, then class 3 as you said, completely processor dependent.
Unfortunately, that still lists a remote controled device as a "robot" when it's really not. OF course, I go by the definition given by Asimov, which includes a mousetrap, but would exclude all "battle bots".
Common usage is anything mechanical that moves, apparently.