When it comes to legal advice, I'm not a good one to listen to, but since no one else answered your question, Here's what I think:  You need to have approach plates, and the normal Foreflight subscription will get you those.  You do have to download the plates for each state you expect to visit.  You don't legally need a paper backup.  The 430W has to have a current database in order to legally fly GPS approaches.  You can fly ILS or other non-GPS approaches without a current database.  That's the way I understand it and that's what I've been using.  You don't actually load approach plates into the 430W - there is no such thing.

Gary