1. for the laser designator, you probably can, but it might take more than scripting (you might have to make an addon)
but i dont know much about addons, so i could easily be wrong
2. for the green light, it can definitely be done with scripting
3. for the thermal goggles, i doubt it is possible now because thermal goggles would require different amounts of light coming from certain objects, and nightvision just puts a green tint and increases the amount of light you can see (i think). if it is possible, i think it will be have to be done by BIS, because it will require a lot of work (im guessing)