The plugs are important and should be pulled and coat the threads with anti seize. They will go 100,000 but the issue now days is plug seizure in the head because they are in there so long. Best to use anti seize on the threads when you replace them. Be sure to use a good 6 point plug socket as they may be tough.
Just adding this if you dont know it already, some head styles are worse for holding dirt then others. Loosen the plugs then blow the dirt out from around them, then remove the plug. It will keep dirt from falling down in the hole. If a new plug is tightened against the dirt and crud it wont transfer heat properly and can burn the electrode tips.
I wouldn't do anything with the wires if it runs ok but be VERY gentle with them. If you ever have issues with the wires only replace the bad wire and go with oem part. Leave the auto parts store wires alone as they are often trouble.
Serpentine belt? If you replace it or if you dont replace it, at least relieve the tension enough so that you can check the water pump for wear. There should be zero "rocking" movement in it.
Don't do anything with any sensors if you dont have a problem. Don't fiddle with connectors etc.
Fuel filter