I just got my H2O yesterday (also coming from a PW1) so I can't really answer all of your questions except about reading stats, because I posted a question about that too yesterday

Unfortunately reading stats are only available on purchased books. There's a separate "app" called Reading Stats under Extras though, which gives you time to read options but you have to exit your book first to be able to access that.
Right now I'm reading a kepub converted ebook and while there are spaces between paragraphs, they're not really so huge as to bother me. Attaching pictures of the screen in book mode as well as the separate Reading Stats screen.