I have a question about blog posts. Is it recommended that they're all optimized (I use Article Jockey), or only the posts that I want indexed?

Well, all posts will be indexed, unless your robots.txt is set to anything different. Obviously your aim is to gain traffic, so yes optimize all pages for the best results. If you dont have the time as there are too many pages, then just do your key pages.

As with anything, the more work you put into optimisation the better the financial rewards.