1) I'll forward the video suggestions to Kriesi.
2) I'll search around - very likely I can find a notification plugin for bbpress. You can subscribe threads with the rss buttons for now.
3) You can use services like http://imageshack.us to upload screenshorts and http://mediafire.com to upload files. I really like the approach of this forum to not allow any uploads. It's always a security risk, causes traffic and storage problems and costs. It also increases loading times because you have to download additional scripts and resources to implement the upload functions or toolbars in general. Only a few user need this feature and they can use external services.
4) I don't like the idea of pn in support forums because:
b) we want to avoid that certain users get "spammed" with how-to requests. I know that it's an advantage of communities that users can help each other. However some users aren't interested in doing our work or helping us out or they even want to charge something for cutomizations we would help users with for free.
That said, I'm glad if users help each other in the support forum. If someone needs the contact data of another person/user he can explain the situation to us and we'll decide if we give away the contact details or not.