Ok, it looks like some things are on the right track, but there are several things, which have been posted in a sticky on this site because they are so important.

Lets start with the plugs and wires. The reason you so excessive wear on the driver side plugs is because the previous set were not the required double platinum plugs. Many Fords are very particular about ignition components, the replacement parts have to be at least as good as OEM. This means Motorcraft or Autolite double platinum or iridium plugs, and Motorcraft or Magnacore wires.

Using a flammable spray to check for vacuum leaks is not only dangerous, but very ineffective. I know lots of people who have "ruled out" vacuum leaks based on this method, then had to go back to square one and repair a vacuum leak. The method only works on painfully obvious leaks in my experience.

The gas soaked plug could be due to it not firing or it could be caused by an injector on that cylinder that leaks down when the engine is turned off. To determine this, you need to do a fuel pressure leakdown test. If the pressure doesn't hold when the engine is turned off, then the fuel is leaking out somewhere, good chance it is one of the injectors, though it could be other sources too.

Your friend is right that the O2 sensors wouldn't cause this issue, but once you get the misfire corrected, you need to replace the sensor. They are designed to be replaced about every 80,000 miles.

On the camshaft sensor, pull that Dorman part back out and get a Motorcraft part. Other people have mentioned problems with the Dorman units.

On the coil pack, it could be bad, but you should have a misfire code if that is the case. I'll assume you have a misfire anyway. Assuming it is the coil pack, don't waste your time with an aftermarket one. Get a Motorcraft or AC Delco coil pack.

I like to get many of my parts at RockAuto Auto Parts in part because the prices are good, but also because they carry the Motorcraft parts.