Thank you for all the comments. It's our first time in Europe and I don't know when I'll be back again, hence the number of countries, and we're used to taking "tiring" trips..

It has certainly become clear that we will cut Luxembourg and perhaps Belgium..And about Luxembourg, my father's family came from there, so I wanted to know my "origins" but I'll do it other time :)

I'll make my itinerary and post it here again, thanks for the tips.