Help Planning Swiss trip in May for Solo traveller

Hello

I would be reaching Basel from Budapest on 30 April evening around 4.20 pm. My wish list is as follows

1>Jungfrau
2>Matterhorn

My plan as i see from various articles is like follows.

30 apr: Arrive to Interlaken by evening stay/or Grindelwald [as you suggest]
1may: take jungfrau express come back by evening [if weather permits]
2may: go to zermatt [here to watch the matterhorn or take the train to gonergrat] [how many days should i spend in zermatt [1/2]
3-4may: go to lucerne [Mt titlis]
5may to amsterdam

I have a return flight to prague on 8may from amsterdam
concerning this how must I plan my swiss trip from 30apr to max 6 May [where I can reach amsterdam]
Since swiss pas is for 4 days cheap and 8 days with no 6 day option should I opt for Swiss half pass

My main outlook is to know how many days I must base in each area so I can do online booking as cheap rates

Any help is highly appreciated