A great collection of reasons, here! :) Definitely having fresh content on your website as a blog offers can help to keep the search engines happy! And if you're rating better on these, then surely that's better for your book sales! :)
That's a great point, Christine. It can be a bad look when you go to someone's site and it looks like nothing has happened for a while. I took a break from my blog for a while and we certainly got a lot less traffic to our site during that time. It all helps. Thanks for commenting.