Can inhaling nail polish be dangerous?

Well - it's certainly not two of the basic elements of a good meal, but neither of these are "good for you". The nail polish is potentially dangerous but, if you're eating dried nail polish off your fingernails, you probably aren't getting enough for it to be instantly toxic. Read the Nail Polish jar for cautions.

As to paper -- it's not harmful unless you eat a lot of it, but it's not helping anything.

Eating things like this falls under the category of an eating disorder. I would strongly recommend you discuss this with your doctor, or an appropriate counsellor.

This falls under a condition called PICA and may be a sign of nutritional deficit. You should discuss this with a doctor.