dont know anything about printers.
1)UV light source and you want the screen under vacuum
2) emulsion's first name is photo; to keep emulsion usable you treat it as if you were dealing with an unexposed film. People used red lights in dark rooms now you can use yellow or even buy sleeves to cover fluorescent lights.
3)Depends greatly on what you are printing and how often you will reclaim.
4) Remove ink with a screen wash then apply a emulsion remover,let it soak a little, then wash out using a power washer. Some people scrub the screen but you can damage the mesh if you don't know what you are doing. Also you may want to use a haze remover if you get a ghost image and degrease before applying emulsion.