<<"I understand it is the "Gateway to the Alps" so I am hoping to at least see the mountains! We hear there are also thermal spas, but I am horrible at geography so I will have to look at a map.">>
And, a time table for the rail travel.
Except that Zürich is not very close to the Alps. I suppose that from way out on the flatlands of the Netherlands, it might look like it, but Bern comes a lot closer to meeting that description, and, if I were asked what town fits that name. I think I'd pick Interlaken.
Belgian chocolates are certainly excellent and set the bar high in any competition. Might be heresy to have this opinion on this forum, but I subscribe to the school of thought about chocolates that "Belgian is best."
However, Swiss chocolates are quite good. Perhaps you had heard that? It is a true fact. ;-) No one ever complains if I bring some back to the USA.
So, I propose an alternative. Skip Belgian chocolates. Make a concession to the rigors of travel ( we all have to sacrifice sometimes) , and settle for Swiss ones. (The Dutch have a proud history of chocolate making, as well, I might add.) Skip the Dutch chocolates, too. (there are some very good ones.) Go from Paris directly to Wengen ( or Grindelwald, or Mürren.) Keep in mind the warnings about "between seasons." A lot of hotels will not be open.
There will be lots of choices of trains to get you there.
Spend as much time as possible at the destination. Have your friend from Zürich meet you at the destination.
As an option, stay with your friend instead of going to Amsterdam.
Depart Gare de Lyon at 0723, arrive Interlaken at 1228.
From Interlaken- 30 -45 minutes into the valley for your final destination.
I like Wengen. Others like Mürren or Grindelwald. Or, Lauterbrunen.
Here is a little bit of data about Wengen:
Paris to Zürich depart same train 0723 arrive Zürich 1126. Have lunch. Meet your friend. Train to Interlaken - depart Zürich 1602, arrive Interlaken Ost 1757.
At your meal at destination by -1900 or 1930.
Have a Swiss chocolate after dinner.
Or, stay overnight at your friend's, and catch the 0521 from Zürich. Arrive Interlaken at 0728 At your hotel for breakfast by 0830 or 0900.