I have been to all the locations on your itinerary, and in general I travel to Europe often. You are like me, I also like to shoot architecture and general "touristy" stuff. I tried many different combinations, and came to the conclusion that most of the shots are taken with my 17-70 (rough equivalent to FF 24-105). Almost never did I use a long telephoto, usually for architectural details, but only because I had it with me. Not any more.
You will see that in old European cities the streets are narrow, and the cathedrals (or arenas, or antique monuments, etc.) are big, which begs for an UWA. In my case - a 10-20 (16-35 for FF). Before I had it, there was no way I could fit St. Croce in Florence or Sagrada Familia in Barcelona's into frame. I also used to take a 30mm 1.4 for inside the churches, but with the 60D, or your 7D I can boost the ISO safely, so one of my two zooms can be used. Better than dragging another lens with me.
Some people suggest a tripod. Please keep in mind that most of the places you are going to visit do not allow them. Many places are so crowded that you do not want even to try to set a tripod. Unless you plan to do some night shots, and do not have something like a beanbag or a small Gorilla tripod, you will be better off leaving it at home. The same with a flash - most of the places forbid using it.
And most of all remember that you are on vacation, you said that you want to see as much of Europe as you can on this trip. So enjoy it, take a lot of photos, and keep the wallet in the front pocket!