my car has run great for the past 2 1/2 years until earlier this year in the spring. since then, it still runs alright, but its just not quite as much of a fine tuned machine as it used to be and its starting to concern me...

Here are all the things my car is doing:
-knocking: it gets somewhat quieter when the car warms up, but doesnt go away completely. it gets a little better some days, but its definetly getting worse over time. its not bad enough to the point where i wont drive my car anymore though...
the motor was rebuilt when i first got the car, but its given me over 30,000 miles without any problems so i dont know if i can attribute it to the rebuild...

-Engine has a "opposite surge" while at consistent throttle: only while in gear during acceleration or while im "engine braking". feels like i lose some powerand then it comes back. and almost feels like a miss. im thinking that a miss is a big part of my problem but i dont know what might be causing it...

-a pretty loud whining noise coming from the cam gears/ top of timing cover: a while ago the idler bearings went bad, so i replaced them, converted to a mechanical tensioner, replaced the water pump, and changed the belt. ive got a hogh volume oil pumpe in there too. Long story short, everything on the timing belt side is new and its still whining. the timing belt tension feels fine and the mechanical tensioner is tensioned properly too. could it be a bad cam bearing?

-High idle while coasting in neutral until the car stops completely: while the engine is warming up and im driving up the street, my idle stays around 2300 rpm after i take my car out of gear and coast to the stop sign in neutral. it usually goes down around 1500 rpm as the car slows down, but it doesnt go to where it should be (800) until i come to a full and complete stop for atleast 2 or 3 seconds. the rpms dont change depending on the clutch is engaged or not. there have also been one or two times where my idle began fluctuating and getting erratic as i coasted to a stoplight, but went back down to normal after i stopped for a second (it contnued til the car warmed up). for all of this, after the engine warms up completely, the revs drops down to 800rpms when i take it out of gear. this is by far the stangest issue, if anyone has any idea what this is i would really apreciate some input.

-a high pitched noise that starts around 3000 rpms, only happens when im accelerating really hard at WOT. this ones really strange because it sounds almost exactly like squealing brakes.

-sputtering when accelerating from low rpms. worse than it should be. the plug wires arent very old, but the coil may be. i put in some new plugs and correctly gapped them a couple days ago and the sputtering got a lot better, but still sounds kind of harsh

-engine doesnt start as easily as it used to

-gas mileage isnt as good as it used to be

-car runs a couple of degrees warmer than it used to

-i pulled my new plugs after they had been in there for about a week and one of them was white. it matches the "too hot" plug in the haynes manual, but that doesnt tell me what the problem might be... i also have to use a sleeve for this plug because the hole had been stripped out a long time ago and tapped. i have a feeling this cylinder may be where my problem is.

i dont know if its ignition or fuel or predetonation or what. one theory i have is that my ecu is picking up the knock and retarding the ignition timing but i dont think the knock is bad enough..
it may sound like i just need a new car, but its not all bad. it works just fine, but everything feels like its off and its really really bothering me. if anyone has had any similar problems in any sort of combination and fixed them i would really appreciate the insight. even if you have a theory, id appreciate the help