Nice artwork, Joe! IMO, yes, these can be installed in attics and crawl spaces.
Switch location is a matter for the building code; here, at least one light needs to be controlled at the access point. How? I suppose even a long string, passed through eyehooks, would qualify. The only time I've been "called" on this issue was when the homeowner was planning on moving the access point.
That said, I sometimes think I'm the only one who hangs these things properly....that is, uses a box, connectors, etc.
Code doesn't really address the issue of lights in these "service" areas...which isn't surprising, as the issue is never addressed by architects, designers, or anyone else.