My opinion was that professors skipped a lot of those technical details due to time constraints. If you're interested in those technical details you can continue to self-study those topics like Munkres Topology, or Mas-Colells General Economic Equilibrium book. We used MWG for learning mechanism design and I found it to be poor. I'd recommend Borgers for Mechanism design. The point is, there are a lot of great books that can supplement your class and provide a well rounded perspective. It sounds like your a self-starter, so consider this strategy.