From Prague to Amsterdam: what to do in between?

Dresden could be an easy stop: only 2hrs from Prague. Another one could be Erfurt or nearby Weimar, 2 to 3 hrs from Dresden. From there it is a long, but relaxing day on the train to Amsterdam, around 7 hrs.

I'm a big logical sequence person. You could go up to Dresden and Berlin but that leaves you hanging. From there I guess you could cross northern Germany to see Luebeck and Hamburg before going into Amsterdam. Or just fly from Berlin to Amsterdam, then spend some days seeing towns in Netherlands.

I'd probably go with a combination of Prague, Vienna, Salzburg, Munich, Romantic Road, Rhine (and/or Mosel), Cologne, Amsterdam. I'd also want to add some other Netherlands places such as Utrecht, Leiden, the Hague, etc.

I define how much time to spend in a certain place by time it takes to see what I want to see. Maybe the southern route has too much too see for 2 weeks?

"...everything is being considered...." How far are you willingly to deviate from a roughly straight line of travel? Logically or illogically? If I'm that desperate to see a specific place or site, that makes no difference to me depending on the time factor.

Any city/town you are desperate to see, ie more than a mere top priority place?

I would suggest these: Dresden, as suggested above, Celle, Weimar, Naumburg an der Saale, Minden, Münster/Westfalen, Leipzig,

Meissen, Jena, Magdeburg, even Berlin or Potsdam, quite doable logistically, depending on your priority there,