Back off sparky, we're on the same page.
What do yout think is going to happen to you when somebody writes up "engine rough," you say, "Whatever, the guy that wrote that down doesn't know what he's talking about," and you depart. Shortly after takeoff, after what seemed like a normal run up, the engine tanks and you put the plane in a field.
The onus will be on you, even though the write up isn't a real, technical write up, because you flew an airplane when you were given advisement that the aircraft might not really be up to snuff. The radio? Whatever. The heater? Who cares. Rough engine? You might be right, the plugs could just be fouled up (happens all the time), but what if something goes wrong?
Depending on the inspector, the FAA may or may not play nice with you. We're not talking about legalities here, we're talking about common sense.