i was to lazy to read all of this but your oil light problem is your oil pressure switch, its nothing you HAVE to replace unless you dont feel like seeign the light. i had mine flickering for about a year. and its probly a suspension arm in the back.

 

i figure thats what it is for the noises and light...it doesnt bother me rt now too much...
i finally got the ac fixed so its a bit harder to hear now(kuzz the windows are closed)
as for the light...im starting to call it my clutch/neutral light..lol
it doesnt really bother me i know the oil is new and full....(i keep checking it to make sure..)
the only thing is that when i go to get the car appraised, the few times i have gone somewhere to try and trade it...and theyre like.."ur a mechanic...y is that light on..?"

 

all it is is the oil pressure switch it like a 50 dollar fix then the light is gone. atleast thats what it was for my car. and i had a squeak in the back, replaced the suspenssion arm and it completly went away lol. that was over a year ago tho, i got the oil light fixed like 3 weeks ago. I was always chekcing my oil.. putting in an additive .. then i found out what it was. lool