Is there's a major traffic jam but then every single car steps on the gas at the exact same time, will the traffic disappear?

Assuming that every car could accelerate at the same rate and that everyone started accelerating at the exact same moment... the traffic level and spacing would not change one bit! The SPEED of the entire flow of traffic would increase but the amount of traffic around you wouldn't look any different.

What it would look like if it could happen would be like a NASCAR Sprint Cup race where all the cars are bunched very closely together like they are in a traffic jam, but all the cars would be going faster and faster until the speed limit or whatever speed the traffic wanted to go was reached. Obviously this couldn't happen in the real world. Many people can barely manage to park a car in a single spot in an empty parking lot. Imagine those same drivers trying to drive bunched together inches apart on all sides at ~65mph... it wouldn't be pretty.

That is impossible. Every driver has a reaction time. If there are 60 cars in a line and each driver take just a second to react and pull away there's going to be a minute's time lasp between the first car pulling away and the last. By which time the first car will have stopped again as will every car behind it.

No. Because there would be insufficient room between cars. As speed increases, space between them increases and this means the jam clears up from the start and the start point moves the rear at a rate of about 1 car per second.

Absolutely

A car doesn't "step" on anything.

One will always stop and cause a chain reaction accident.

Yeah.

can i see that magical conga dance trick

No.