I'm not sure, but just know that the art will add to the size of the file. I've pulled my album art off of amazon most of the time without thinking twice. Though it has to be in a format that the player supports, so no png images, go with jpeg. Yes it needs to be in every song Yes, anytime the player disconnects from a computer it checks itself. As far as I know, no. I've never used mine for that long, so I dont know.