Wow, I'm impressed by your photo-walk! To me Prague is one of the most beautiful cities in the world, I've spent there 1 very happy months of my life where my future husband proposed me, maybe that happy memory makes Prague very romantic for me :) It was very pleasant to follow your route and remember the familiar places. The only thing that surprised me was amount of people on your photos that definitely was really veeery small compared to what I remember. Thanks for sharing and hope you will find some more time for similar walk in another period of the year maybe!
Best time for visiting Charles bridge is around sunrise. That is time when most tourist sleeps.