This was all free information I found online in less than an hour, that gives me some great ideas for content, partnerships and potential tools to build into my site to be relevant and useful to my target audience. Of course this is just some quick loose data, so I'll emphasize again: be careful where your data comes from (try to validate when possible), and think about how to use your data wisely.
If you havent see it already, check out the links in shor's comment below - there are some great resources in there. In some cases you can also consider surveying your current audience or customers through email, on-site surveys or SurveyMonkey. Be sure to ask for some profiling information that you can use for determining specific persona needs like age, sex, location, etc. (Probably best not to make it sound like a creepy text chat like I just did though...) :)
On the other hand, I'd like to know how many people constitutes your new experience as an indipedent consultant? Infact, as others noted in the comments here, what you suggest is perfect especially for an in-house SEO situation or in for an Web Marketing Agency with at least 5/8 people working in. Even if all you say is correct and hopefully what everybodies should do, I honestly find quite difficult to dedicate all the amount of time and dedication in order to check all the steps described in your post. Or, at least, I cannot imagine myself doing it for all the clients.