Thanks to the new terminal all mainline and international flights are in the same building, so 1 hour seems sufficient to me. PHL-DTW and DTW-AMS are both operated by NW, AMS-NBO is operated by KLM. Since you are only connecting to an International flight at DTW, you should be fine. If you were connecting from an international flight that would be a different matter. I'm not sure about that lounge part though. The best lounge is one's own opinion. I don't have a much of a preference for DTW though.