Could be in need of a tune up.
lower rpms use less gas higher rpms have more power
change yer fuel filter?
It may be the heat shields on the exhaust system vibrating.
major vacuum leak?
If you do not reach the read zone in your RPM scale, you are fine. Just make sure that you are using a good coolant and thermostat. I would even use low opening temperature thermostat if you like to drive with high RPMs often.
Most likely, the problem is the ignition coils, though it's a good idea to change the wires while you're in there.
no
You did't provide the year/make/model/engine, but...The throttle cable/ throttle spring can be faulty/sticking. Another possibility is there is an air leak, after the throttle blades that is allowing the engine rpms to be high at idle. You can check vacuum line to the intake manifold for damage or the AIC (air idle control valve) for being stuck open.
did they want freedom
Obviously depends on RPMs. Normally 15-20psi at idle. Could be as high as 30-40psi when the engine is under high RPMs.
Because your motor is spinning faster at higher speeds causing higher rpm's
Because the RPMS go so low at 1000 rpm it shut down or you just hane bad fule injection the same thing came to me.