Backlinks are everything. Nowadays, I think you have to try pretty hard to produce markup that Googlebot can't interpret.
I rocketed my forum community to the top of Google by generating backlinks. Some people consider it grunt labor, but I found it a lot of fun, especially if you get a program that keeps track of your rankings. It's addictive.
And this is forum software that is rife with duplicate content, has URLs like `/?forumdisplay=22952920&v=92348232`, and is so unSEO that a third party company started up to sell an expensive product that SEO's the softwre via plugin.
Guess what, despite all the little marginal tweaks and SEO obsessions I don't sweat over, Google miraculously figured stuff out. Backlinks are obvious and they work. It's the reason why you can overtake encumbent #1 rankings that have no backlink campaigns.
That's sort of my point. I mean, getting links to your site isn't exactly a secret, this has been key since Google first came on the scene. Sure, it's hard work to have a reputable site and to promote it correctly, but it's not rocket science. In fact, it's pretty typical common sense.
I get the point about duplicate content, that's something I had heard but not really delved into because, well, decent architecture usually means not having that sort of stuff around.
The more I hear SEO "experts" go on about things, the more I think it's a bit of a scam. Scam is probably the wrong word, as I'm sure many SEO people are well meaning, but the more I look the more it all seems like snake oil.
I think what you're getting at is that the majority of SEO is pretty straightforward - I know what you mean about rarely discovering something new from SEO sites. The final x% is a bit more challenging.
At one point I put together a pretty basic site with one backlink and barely any attention to content and accidentally ranked #1 in Australia for "make money". One particular page on that site is four paragraphs I threw together and it's made $24k in four years for no effort since. I've had a few other events along those lines too, mostly leveraging the past property I built up and using that as a backlink.