When Gerard Salton was inventing full text indexing he was working with a set of 80 documents encoded on Hollerith cards. In that case the problem that you miss a few documents in a query is the main problem because you don't have many documents to start with.
Google indexes "billions and billions" of documents and they don't feel the need to index 100% of it. It costs money after all. They need some indication that your site is worth indexing, not just one or two pages at the top, but the whole thing.
One part of "look like a blog" is that sites that are updated frequently are treated differently than sites since it is (1) an indication that the site is of value and (2) takes extra effort to index a frequently updated site. So if you can get in the "frequently updated" class that is helpful.