Cycling on highways I'm pretty sure is illegal everywhere, thankfully.
I'm also an advocate of taking up a full lane, but the laws in many places (like New York) actually require you to ride to the right/shoulder where feasible. Unfortunately that's not really clearly defined, so even though you have a legal right to a full lane, cops will still give you a ticket.
Having narrowly avoided being doored a few times, I won't ride anywhere within a foot's range of a completely open car door.
I am not saying go crazy and ride your bicycles on freeways. This is more about city streets. That being said, I truly believe the way to have fewer cars striking cyclists is to have more cyclists assert themselves on the road.