Well, it seems that these queries are the default queries of WordPress. I’m looking for a good solution, too. W3TC works well, but … you wrote it. I think there is no need to use 20 queries for simple pages. I googled a little bit and there are tips like setting “return true” in is_blog_installed() in functions.php of wp-includes. But after an upgrade you’ll have to change these lines again. Would be cool if many people could post their boost tips and we make a collection. I think there are some hidden unnecessary queries. yoast wrote 2009 that he had “only” 16 queries – 7 of his plugin and 9 from wp itself … https://yoast.com/wordpress-performance-optimization/
any ideas?!