I know illuminated items do (like the illuminated tree, heart etc), but I was wondering about streetlights. I want to place about 4 or 5 in my town down one path, like an actual street, so do you think that would be too much? Thanks for your help.
I don't think streetlights will decrease your rating. At the very least, they're neutral to your rating. They're fairly cheap to build anyway, so you could just build them and see if anything changes.
My villagers routinely tell me how much they like the streetlights in my main town. I don't have that many yet in my other town (just one, near the train tracks) and my villagers there keep complaining about how dark it is. I think it might have a positive effect if anything.