While I have not done a factory reset on my VIM or VIM2, I do not believe a factory reset will harm your VIM2.
I have done a factory reset on other Android TV boxes, no harm resulted. Box booted like it did the first time. What, if any, remnants of the previous user/system data survive the reset, I cannot say.
NOTE: If the firmware on your VIM2 has been updated since you received it, a factory reset will not take you back to the original firmware.
I am not sure there is a difference between the two terms, hard reset and factory reset.
A google search revealed this(offsite link).