GAnderson,
1. Yes some of the NV scopes, those with variable power work similar to a regular scope however there is a catch. First you have to have NV power to see at distance. It's referred to as Gen 1, 2, 3 with 3 being the best, usually seeing more detail at greater distances with less light than say Gen 1, but comes at higher costs $$$.
Also, many of the NV scopes are digital zoom vs the optical zoom in conventional scopes. Digital zoom uses pixels like a camera and the higher zoom the less the quality of your view.
2. There are NV scopes which mount just like conventional and there are "clip ons" which attach to your conventional scope and give you a NV view thru your conventional scope.
3. Thermal is not NV. NV helps you see in the dark. Thermal helps you identify heat sources and work both day and night. When you look through thermal, all heat sources appear highlighted. An animal, a person, a hot vehicle hood stick out like a "sore thumb". To a certain degree, thermal also helps you see in the dark but not on the same level as NV. Thermal basically gives you the highlighted outline of a warm or hot object.
4. There is "no end" to it. You can pretty much spend as much as you want on this stuff. For some, like me, looking through thermal once was addicting to the point "I had to have it" sorta like heroin I guess although I never had that lol.
