No there is no reason for 2 forums lol as we already have one that is working fine
We don't have a problem with our current system but there is always room for improvement. The visual make over is only if you can make it better.
With the forum and main website we would integrate any changes onto to our server.
The forum being inside the page like the "big dogs" as you say can work if done correctly but this does not mean it is correct. But you can not lose too much space to the main site as forum users need to be able to see more posts on the screen and are generally aware of what the parent site is offering. How many people need to go to the current SDN once they have seen it. Again the idea is good but needs a lot of thought on ergonomics.
Linking user registration: We don't need users to be able to register with the main site but once they purchase Skyline, their account login will need to provide access to the forums, purchased downloads, shopping basket of asset store and advanced tech support. This is a little while off yet so no need to worry there.
vbulletin : We can not use someone elses licence lol this is not the thing to do, so I don't think we will go there.
Website: Some of the ideas you have developed in your website design I think we can add to the current site as they will be an improvement. I did like some of the earlier versions you made ( a week or so ago), the current one just has too many strong contrasting colors ( text and lines most notably). We should hook up on skype so we can chat to you easier about this and how to progress.
aurasoft logo: Looks great I think we can use this.
Skyline logo: This is moving in the right direction, like the "Y" idea and how it separates the text. It does need to be polished more though before we can use it.
I think that all for now, thank you for your contributions so far keep it up