Over revving when starting engine

Check for vacuum leak .and check pcv

If I am hearing you right, the engine revs ONLY when the clutch is depressed?
I would have to doubt that is what is really happening, tho. Is it possible that the engine is revving from the time that you start it, until the time that you shut it off?
This would be more likely, as depressing the clutch doesn't really have any effect on the engine, other than dis-engaging the drive-line...
IF it is revving at start up, see if it isn't only 'idling down' when the weight of the vehicle puts a load on the motor. In other words, does it idle down, or does it only SEEM like it is, because now it's pulling the car? Do you have to give it gas to go on a flat surface? If not, then it's still revving.
Then, if you decide that it's revving ALL the time, you will need to check it for vacuum-leaks or mis-adjusted linkages, or carburetor (throttle body, if it is injected).
Do yourself a favor and buy a Chilton or Haynes manual for your vehicle (at most any auto parts store), if you plan to keep it for a while. They will generally have troubleshooting sections, to help you eliminate variables until you find the actual issue. It's the best $20 you can spend!

I would definitely have your Idle Air Control valve checked/replace....I've had them stick at around 3000 rpms, even while driving, and couldn't stop the car without turning off the ignition first....

Your clutch needs to be replaced.

Hello there,

This is a normal operation, all your doing is hitting the rev limiter. It's there to protect the engine from over revving. The Powertrain Control Module or PCM cuts fuel to the engine intermittently to keep the engine from revving past a predetermined RPM when in "neutral", and in "park" if it's an automatic. Just in case something like a foreign object or a small child or animal were to inadvertently depress the accelerator pedal and rev the engine too high and damage the engine in result. I hope this info helps, and just for peace of mind, I am a Master Certified Ford Technician. Enjoy your new exhaust!! I'm sure it sounds great!!

thrust bearing thats all .

If the car rev'd up but did not speed up at the same time the clutch is starting to slip. Check the adjustment and recheck driving. When the clutch starts to wear this is how they act, only most people ignore whats happening and keep driving till adjustments won't fix it and the clutch has to be replaced. Have adjustment checked and keep an eye on it and hopefullty you won't need a clutch yet.

check under dash where pedals are as there may be wiring there that the pedals are touching and shorting out

Have you tried the O2 sensors?

The grinding sound may be a throw out bearing or the pilot bearing. The sticking throttle problem sounds like a linkage or cable binding up from possibly damage due to the impact from the accident.