Itinerary advice for 6 days Switzerland, September

Hi Thank you very much for such a great site in providing the useful information about visiting Switzerland.

We are a couple planning to spend our honeymoon in Switzerland, following our trip in Italy. We intend to use Eurail Select Pass for most of the trips. Scenic/nature trip are our preferences.

We have worked out 2 options of the route both entering from Milan and exiting to Paris, and we are not sure which one will be better.

Option 1:

20/09/2018 Thu Day 1 Milan -> St Moritz , taking Bernina Express (Via Tirano)

21/09/2018 Fri Day 2 St Moritz -> Zermatt , taking Glacier Express

22/09/2018 Sat Day 3 Zermatt -> Interlaken/Wengen , Afternoon: Lake Brienz Boat Trip

23/09/2018 Sun Day 4 Interlaken/Wengen, Jungfraujoch/Trip to Lucerne or Montreux (Depending on weather)

24/09/2018 Mon Day 5 Interlaken/Wengen, Jungfraujoch/Trip to Lucerne or Montreux (Depending on weather)

25/09/2018 Tue Day 6 Interlaken/Wengen -> Paris

Option 2:

20/09/2018 Thu Day 1 Milan -> Zermatt

21/09/2018 Fri Day 2 Zermatt -> Interlaken/Wengen , Afternoon: Lake Brienz Boat Trip

22/09/2018 Sat Day 3 Interlaken/Wengen: Jungfraujoch or Trip to Lucerne/Montreux/Geneva (Depending on weather)

23/09/2018 Sun Day 4 Interlaken/Wengen: Jungfraujoch or Trip to Lucerne/Montreux/Geneva

24/09/2018 Mon Day 5 Interlaken/Wengen: Jungfraujoch or Trip to Lucerne/Montreux/Geneva

25/09/2018 Tue Day 6 Interlaken/Wengen -> Paris

which option will be better? Any Recommendation/Trips for Option 2 ?

We have read somewhere that for the Jungfraujoch trip, one can go up by cable car and return via a different route to have a different experience, any advice how we should go about doing that? Any suggested route please?

And one last thing, should we take the Bernina express bus from Lugano to Tirano?

Thank you very much!