Guys, this isn't about white hat vs. black hat. This is about site organization, and how your site organization can help Google understand what's happening in a mechanical language they understand. If you do it correctly, it will help your rankings regardless of your techniques.
I'm just glad that there are a few people here that really get some of this stuff.
@Satans_Apprentice what I like about your comments is how you were able to see results just from strengthening the silo (without links). That says a lot.
By the way, if you want to know about another widget that will help you out on all of this, check out widget logic. I know you will get it.
301's automatically redirect everything to the new page. Google just needs to have visited your site and see the redirects. Their spiders are always looking for old links, and they need to resolve to a page, or else it creates errors that this and that page doesn't exist. So google wants and expects a 301 when things move. Websites change architecture all the time.
Under your theory no one could ever change their website. It doesn't work that way.