Hmmm... a bit tricky, seeing Lübeck and Neuschwanstein are at opposite ends of the country. You'd be spending a lot of your time in transit....

You mention Munich Airport but not Munich itself. Did you want to visit the city as well, or are you just visiting the airport? (On business?)

I guess if you're not planning on spending time in Munich, and all you're going to do in Wuppertal is ride the Schwebebahn, then it's quite do-able. You really want to spend a day or two in Lübeck - it may be small, but there is so much to see, and so much history.