CustomHosting

All the thing you've said, maybe add a company blog if possible, constant new content is well liked by google, social networking is worth it if you can spend the time, but also relax a little, if you've just finished the site you need some time to pass, you need to be indexed by google, have your links on other sites/directories indexed by google, and also google adds extra points the older your site gets, so just waiting a few weeks/months will naturally see your ranking rise.