Barrett -

There is no reason for the module to create roles (that type of behavior is highly discouraged for a number of reasons), instead the module allows you to create any role you desire and then assign them (via module permissions) to one of 2 permissions levels specific to the blog module: Bloggers, Ghost Writers. Likewise, you could assign individual users these permission levels (just like edit and view work today using the same grid). 

As for your logout problems, this most likely has nothing to do w/ the blog module (I cannot reproduce it for one and it shouldn't be related understanding how they both work). 

The difference between the forum and Community Exchange: There is a long explanation behind this but for the sake of simplicity: Questions that have answers get asked in the exchange, it is not meant for discussions. If you use this forum thread as an example, there are several questions here (not 1 question w/ 1 answer). This type of discussion is not appropriate for the Exchange. Even you have asked 2 different questions (in 2 posts) and made 1 post of comments, this is not good for someone looking for answers (so they don't have to ask a question that was already answered).