Thermal devices have to calibrate when first turned on, so the image may not be quite as clear when it first starts.
This is water resistant, not water proof. The image color will depend on which color palette mode you select, there are white hot, black hot, green hot, red hot, and multicolor modes.
While it is an iconic Hollywood effect, you won't find any thermals that make a similar sound out of the box. Most thermal devices are extremely quiet if not silent.
There are multiple color settings.
You should be able to, although the ambient temperature will determine how far and easily visible it is.
No. Thermal imaging devices do not need infrared light.
No, Leupold advises against mounting to any firearm.
This should be able to pick up a rabbit in brush with snow as long as it's within detection range. Because of the smaller size, your effective range will be reduce from the normal 600 yards down to probably around 400 yards max. At that distance it would only be location identification, you would need to be closer to actually ID the target as a rabbit rather than just a heat source.