This is personal preference, it is recommended that you have enough space where you do not come into direct contact with the heater.
No, it is not recommended to be mounted on a fan.
Yes we have hook up under or ceiling fan during the winter months.
The blades fold down
It is not a fan, it’s a heater, doesn’t spin
No, that’s all it does is heat, it doesn’t spin, unless you just want to stare at it
Yes, this can be used.