1. You can use the rich text editor to set normal things like font, bolding, etc. while you write. Or use actual HTML tags and do it from the plaintext editor, but there's no official place to do things like set the background colors of the pages. There's a way to make things better for you, though, with the site extension (
edge/chrome). It has dark mode and updates everything to look a lot more modern. Also works on
Firefox, if that's your gig
2. Not officially, but since you can use HTML, yes. I don't have all the specifics for that, but google would. Just try to warn people there's music (if it auto-plays) and make it toggle-able if you can so I don't have to mute the tab if I disagree with it or anything while reading. A much easier option is to just link to a YT/spotify playlist or something in the description
Good luck with the writing!