no issue for newborn, the light is very soft behind the soft plastic belly. I didn't notice the baby feel discomfort with the light (e.g. bright sunny). And you can always turn the back facing the baby (little louder music too because the speaker is facing the back).
yes, suitable for newborn. The light is a muted amber color, dimmer than a night light and the music is very soft bubbles and music. I bought it for my newborn granddaughter and she loves it. If you are concerned, just don't turn on the electronic functions until the baby is older, but I don't see it as a problem.
Yes I would use it on any age child! It is soothing and restful and helpful to mom. You squeeze the tummy on the horse and it glows but not too bright! Hope this helps. By the way the music is not too loud either.