When do you want to travel?
If you want to visit lakes, I’lld suggest keeping the Netherlands and Belgium for another trip.
One week is not much, so slim it a bit down. A lot of lakes south of München, or East and West of Salzburg.
This summer I had a nice time at the Lake of Bohinj, in Slovenia. I can reccomend that, probably a better destination than lake Bled ;)
Without knowing where you are in France, I would consider heading for Lille or Strasbourg, then across into Belgium or Southern Germany or Basle on your first day with a Global pass (One of your 2 days allowed for travel in France.) Then you could either target a circular route between the 2 and return back from the other, or a circular route back to the start.
This opens a couple of general routings - From Lille you can head towards Brussels to connect with the regular Brussels - Cologne - Frankfurt ICE for a circuit along the Rhine, down to Freiburg/Heidelburg and the Black Forest, or even to Munich and Vienna. From Strasbourg yo can easily do it in revese, or create a run across Southern Germany to Vienna and Budapest.
Given you only have a week and limited funds I would suggest the first plan and keep Switzerland and Vienna options for when you have more time and funds.
I have forgotten to say it would be a one week trip,and I haven’t got a lot of money for the moment.
I had a similar trip last summer, wanting to visit smaller cities, easy to get around on foot. And not too overwhelming.
I went to Bratislava, Brno, Leipzig, Utrecht and loved my time in all of them. I don’t think there is anything to worry about in terms of safety, as long as you take the usual precautions.
Where will you be starting from?
I think in Germany or Austria but I don’t know where to begin. It depends if I go in Eastern Europa or if I go to the Netherlands. But I want to see the countryside and some lakes...
Yeah, Salzbourg could be a great idea (also tosee Mozart’s house), and I plan to visit again Germany. Maybe I would plan it for june/ july or sooner if I have the time for that. The thing is that I can’t go to far from France because I would be obliged to have a long train trip, or to go by plane, but Germany and Austria would be great.