Nope. He's written a lot within a clearly defined scope "the human side of software development", so his articles are often related. Beyond that, self-linking is a great form of self-promotion and getting readers engaged in a blog.

Maybe. That was the style of the day, and Atwood's blog can easily be read sequentially (such that the self-references aren't necessarily self-promotion so much as they are helpful reminders of previous concepts).

At least, I spent a summer in 2008 reading through his blog.