I have a Kindle Fire and it's my second Kindle in 15 years. Years ago, you couldn't download from the library with a Paperwhite; it had to be a Fire. Not sure if it's still that way or not.
I do download my books via email from the library. Our library uses an app called Overdrive which I think is going to change to something else next year.
I don't notice any odors nor does it give me a headache.