Recently I've noticed instances of Google Chrome Helper remaining running in my activity monitor long after I've shut Chrome down completely. Are these just hung processes because Chrome Helper is buggy like that, or should I be worried? They don't show as non-responsive, just... running all by themselves without Chrome itself.
It is safe to stop any process named "Google Chrome Helper" as it is only associated with Google Chrome. Since Google Chrome is not open, it is safe to stop them. This answer may help.