1: That is a really cool idea and something I have been thinking about since day 1. I want to be able to show a graph that displays the relative change in opinion over time, annotated with the addition of new citations to the Viewpoints. So when someone updates the Ember Viewpoint with new information and the citation for it, you can do some basic "cause analysis" on what changed,when and why :)
2: Absolutely makes sense. We are still debating the best way to do this, but one simple solution is an editable comparison matrix that shows the simple features/specs that the Viewpoints have. The ULs would then be used to further flesh out the more significant points that can't be explained in matrix format (for eg how nice the UI is for a particular app)
3: Again, we debate this point all the time. What do you think about the phrasing "What are the different programming languages suitable to learn first?" or something along those lines?
4: Awesome idea, we are going to add additional login options soon, but the idea of bringing in external rep is very interesting!