The elektraDRIVE motion control systems can be used in an interview setting, however they do not have a looping capability. In order to have a looping move that goes back and forth on the slider automatically you would need to go with a digital motion control system like Second Shooter or CineDrive.
The amount of noise that the motor puts out is directly related to the RPM's that the motor is spinning at, we offer 5 different elektraDRIVE slider motors with different gearing ratios for use in different shooting situations, for an interview setting we would recommend using either a 50 series or 100 series motor. Their fast gearing ratios allow you to get a desired speed of cart movement on the slider without needing to turn the speed (power/RPMs) of the motor all the way up thus putting out less noise.
In this video we show a motor speed comparison between all of the elektraDRIVE motors and also performed a decible reading: