as for your spark plug problem, this happens because origionally the factory suggested a type of plug that had an extended threadded shank on the plug and carbon can build up causing it to prevent the plugs from coming out easily and it also wipes out the aluminum threads if you force it out. Unfortunatly if you want to change that plug you will have to force it out and then go back with a helicoil spark plug kit (14mm). And when you go back with the new plugs there are new plugs that are shorter and will not suffer this problem. Check with your parts supplier/dealer about this, they should know about it and have the correct plugs to go back in the engine.

Since you verified that the coil packs are good i would check the wiring harness where they plug into the coil packs for broken wires. Also swap the egi relays around with the other relays and see if this helps, after clearing the codes (using the pedal dance) if they do not return you know the relays may have been the cause and you can replace them as needed. Have you checked all the fuses in the fuse box and made sure they are all fully inserted into their sockets? Sometimes these fuses can work loose and cause problems.

One other thing, sometimes when replacing the crank or cam sensor it is advisable to replace the opposing sensor, if you put a crank sensor also replace the cam sensor, and visa versa. They both do work together in the ignition system and either one can trigger this code. (since you've done this it is unlikely these are causing this)

If you've verified wiring, sensors , spark plugs are all good my only other thought would be the ECM itself, make sure all the connectors are plugged in and locked, you may even want to put some electric silicone grease in there to help waterproof them. And check the frame ground and make sure it is good, remove it and scrape any paint that might be underneath so it will have a good metal to metal connection.