Yes. Official support for uploading PDF and unencrypted EPUB over USB but the interface is designed for annotating instead of reading. koreader or plato can be installed (unofficially) for a much better reading-first experience.

Sure. But be warned it doesn't support Adobe DRM ePubs and the ePub support is really bad. Like worse than a 10 year old Kobo bad. PDFs work fine.

For book reading look at literally anyone else in the space. Kobo, Amazon, Boox, Boyue all make 10" note takers now and they'll do a better job at displaying books.