[eluser]Dam1an[/eluser]
I now know what you mean when you said you keep changing your thoughts about the structure as soon as you finish with a structure... Except I find myself changing my mind before I even get half way through the structure :S
As for the get_post passing back an object, you thinking of a datamabe obect (like in CI) or creating an object, settings its args (or it being set by the constructor) and passing back the object? Both work in much the same way once you've received it, but will make a difference on the way you choose to implement it
One thing to consider (which you've kind of talked about) is in what situation will [otential users integrate this system with?
Eg if its mostly going to be integrated with frameworks, then MVC would be the way to go, but you'd probbaly alienate users who have a home brew PHP app
If you do it OO, wrap the forum object as a library, an interface to the stuff like config etc, have your views broken down already, so it could easily work in both scenarios
