Nice website. It sounds like you are thinking along the right track, but here are my thoughts based on your question:
1. If you do decide to use more keywords, be sure to use the exact phrase for which you'd like to rank in a very limited number of places, but be careful not to over do it with keyword usage. It's very easy to cross into spam-land on this with G.
2. Web design in a major metroplex like DC or statewide for VA is competitive and consistently raking highly for this if you are not will likely take some time, particularly as web firms tend to be very active online. Having said that your site is established as an analysis of your link profile could also be helpful in planning what is needed as far as anchor text and types of links.
3. The key to local SEO are citations and high quality, relevant content. Citations include the chamber of commerce and BBB, both of which you mentioned, so again you are approaching this correctly. The real key is to be thorough (go through the usual citation list an then I recommend whitespark.ca) and to start with your Google Local and Bing Local accounts as those are the lowest hanging fruit. I have not done a full analysis, so I apologize of you have already done some of these steps and I am covering them twice.
The following is a blog post on how to properly build citations (full disclosure, I am the author).
http://www.digitaldiameter.com/marketing-blog/build-local-citations/
Let me know if more detail on any of this would help,
Michael