2003 Mountaineer 4.0flex issues

[Genery]

Bought a 2003 Mountaineer 4.0sohc flex with 246000 miles or so. When i got it it had 1)a broke exhaust manifold bolt on the passenger side, 2) both valve covers leaking all around it seemed like, 3)intake manifold gasket leak(sprayed carb cleaner and heard it rev up when i sprayed around the gaskets there, 4) Pcv valve on back of drivers side valve cover just hanging there halfway in; no threads left in the valve cover, 5) the hightemp/lowoilpressure combo, 6)slight hesitation or miss (rythmic vibration at idle goes away when accelerating) feel it right under feet on drivers side, harmonic balancer was coming apart replaced it, radiator cracked replaced it, chain guides looked good as far as i could see with the vc off), replaced tensioner and pulley, belt, fixed the manifold bolt, vc gaskets, intake manifold gaskets(needed helicoils due to previous overtightening), cleaned maf, egr valve, throttle body, oil pressure dummy switch was a cheap aftermarket so i got the motorcraft. It was 2 mm shorter on the threaded end and tapered, unlike the aftermarket part(hasnt come back on yet after 250 miles), Looking at the service records i noticed the oil pressure light first appeared at 162000 miles(the next oil change after the plugs and wires were replaced) noted as arriving with the light on. So i pulled the plugs and they were bosch iridium gapped at.045 and white on the tips with a single burned spot on the ceramic insulator of every plug straight down from the outer electrode. I checked and the oem calls for motorcraft sp500 gapped at .054. The motorcraft heat range is 2, bosch i took out was heat range 7. That was just odd to me, wondering if the heat range may have caused any damage due to different heat dissipation.Was hearing ping noise from drivers side now its barely audible. I still have a rythmic "surge" OR "Bup" noise from the same side) it seems like. Pcv is tight and not leaking anymore but i put paper on the oil filler and plugged the dipstick and the paper blew off. So i guess im wondering if i just did all that to diagnose a worn out engine. I guess im hoping someone tells me im wrong.