Engine slight "shiver" at idle- normal?

[Vitalie]

that vid. is set to private, so link fails.
fixed it and added one more for gauges.

http://youtu.be/NTkipnBrrx8

https://youtu.be/dJ_Jnc3JjNM

shivers. (is this in neutral?) Yes
hot or cold engine or both. Only when hot and idle at 800 rpm
is RPM hot 800 , plus or minus , 50 RPM? Yes
does RPM hunt , at any time hot? tachometer moves a little while I feel that shake.
is shivers, RPM variance< or a sound only, ? I can feel it, hear it and see it on tachometer.
this car has automatic, IDLE controls. and will hold idle tightly, hot.
one test hot is thrown on A/C , blower to high then, head lights then rear defroster. at once to see if RPM goes way low. (and sticks too low ,or takes 1 second to recover) the rpm jump to 1000 when AC on
it must hold 800 hot. if not the ISC system is failing. (that dont mean its bad, just that it can't handle some problem with air or fuel,etc)
the idle will not work if the Idle switch in the TPS is bad or set wrong.(calibration)
a voltage test at the TPS solves that riddle. fast. backprobed. after all additional info you still think this has to be done , I will need more info how to do it.

if the shiver is sound only, not RPM surge, its most likely the tins, near the CAT making noise, or loose exhaust manifold shields. or something else loose but is not normal.

Thank you