Of all the tools I've used over the years, the Google SK tool is the most useless. It looks really good and really easy to use - and perhaps that's the problem. It just doesn't give nearly enough information. Too little detail. And with SEO - that's where it all happens.
SEO is a strategy. PageRank, SERP's (Search Engine Rank Positions), Alexa scores, Website valuations, keywords and titles - these are all symptoms of the implementation of a strategy. SEO isn't a checklist of things you need or have to do. Some of them are accidental or even intentional red herrings.
When you read all the many blog posts and news articles on SEO (and Internet Marketing), many of them are just written by people who want to be good or think that if 10 websites say the same thing, it must be true. Many are just looking for a website that can grow extra income on the side. "Work from home" ads in the classifieds were huge in the 1980's and 1990's and they're still going strong online.
Stop looking for a checklist - develop a strategy.