You wrote in some good details. Better than most posters!

The "vroom" tells me there is a miss happening and the ECU is self tuning like its suppose to.

I am not a great fan of Champoin spark plugs. I have had bad ones right out of the box!
Ignition components are new so I will stop there.

I think a lean mixture could cause issues like this. I want to blame the computer's Engine Coolant Sensor first. I forget which way the voltage goes on the O2 sensor but staying high is not good and it is telling something is burning strangely.
But if you have a slow sample time voltmeter, you might not be getting the whole story.

Loss of power and pinging is a symptom, if you are very lean. If the plugs have been in there long enough they might have a white or no deposits. One different plug in the bunch should not be there.
I am thinking they are all too lean or burning the same with a miss rotating or even doubling up briefly.
I assume oil consumption is not a problem to cause excessive carbon for a ping or rattle.

I would still check the timing belt first at the cam notch and distributor rotor to be exactly under number one for good measure. How long has the belt been on it and when was the last time it was adjusted through the front cover?

Loss of power and rattle is a higher speed and loads issue. The Driving symptom could point to the belt by itself.
Does it do an instant hit and crank up, hot or cold?

Good luck on that vacation
Phil