My suggestion is to allow target audiences to select a homepage that contains buttons/links to focused content for their specific audience: Admins, Faculty, Students, Instructional Designers, Developers. That might make it easier for the different audiences to locate content based on their goals/needs.
I prefer Mockups #1 and #3 because they have some focal points. I like how searching is central on #1. #2 is overwhelming without having some content emphasized.
Getting information and answers is why most of us login to the Community. So, another idea is to prioritize, centralize and emphasize anything that provides quick information/answers such as guides, searching, and discussions.