Get some freon, spray the spark plug real good for about 45seconds, spray some wd-40 down in there, turn the motor on and idle it at 5,000rpm for about 45seconds... Sucker should pop right out!
This is going to sound crazy but get a spray nozzle with a tip make sure that the tip can fit within the socket and inside of that spark plug hole as long as it fits past the socket and you can blow air through the socket into that contained area it will build pressure and the socket should pop out
I understand your frustration first of all if you used the right size socket it shouldnt even get stuck. Second if its stuck that means you had to exert pressure to put it in when my problem is usually the socket falling off my extension. Third did you try getting a magnet you named every other possible tool but magnets work really well when trying to grab metal way more effective than a vacuum. Sorry youre having to do this but call a professional to extract it before you ruin your engine. A tap should never enter the spark plug chamber and a power tool shouldnt either!
When you're a parts replacer who buys their tools at Harbor Freight, you deserve every bit of frustration you give yourself. Every good mechanic would have used quality branded tools, (Snap~On, Matco, MAC, SK, etc) and would have either never run into that issue, or would have the common sense to know how to take it out. P.S. Why don't you take the valve cover off, then remove the spark plug tube and the socket will more than likely come out with the tube.
