1) There's a fair amount of free stuff. "Worthwhile" is up to you to decide. Mostly recent episodes of various TV shows.
2) I'm not sure what the "official" maximum length is, but it's not likely to be something you'd have a problem with assuming the connectors are in good condition and wired correctly.
3) Plus it into your router, and it should magically work (after some setup). You should have some basic knowledge of how your home network works though.
4) Same here. I think the online VOD is fairly new (today's the first I heard of that aspect), and my self-serve account is very old. I suspect we'll need to call Support to get something tweaked.