You won’t have time for everything on your list, particularly to do both the Schilthorn and the Jungfrau, or the Stoos peak experience. And I assume you mean to just see paragliders, not go paragliding yourselves. You won’t have time for that unless you give up most of the other things you list.
However, you can include most of the rest—-Mt. Pilatus, a lake boat, suspension bridge, Grindelwald Cliff Walk and walk to Bachalpsee, and waterfalls. You would ideally need 2 nights each at Luzern and Lauterbrunnen, which you could manage by spending your arrival night OR your night before departure in Luzern instead of Zurich. Depending on the actual timing of your flight in or out, that could work, as the train trip from the airport to Luzern is only one hour. And depending on which of those works, you could start in Lauterbrunnen or Luzern, and end at the other.
This would give you one full day and part of another at each location. Activities to include:
From Luzern, take the cablecar route via Kriens up Pilatus, then down to Alpnachstad by cogwheel train. From Alpnachstad, you can either return to Luzern by boat, OR take the train the short ride from Alpnachstad to Engleberg and ride the lifts up Titlis for your suspension bridge experience on the Titlis Cliff walk: the first bridge depicted on this page:
Then return to Alpnachstad and take the boat back to Luzern, or leave the boat ride to the following morning, before you travel to Lauterbrunnen. The train ride from Luzern to Lauterbrunnen is 2h 19 minutes and part of the scenic Golden Pass route. You will pass a lovely waterfall near the Brunig Pass.
On arrival in Lauterbrunnen, after dropping your luggage at the hotel ( book a room with a view of the nearest waterfall if you like). you could walk to Trummelbach falls and experience the “inside the mountain” views of the falls. Or head up the Schilthorn if that is still on your list. If you choose the Schilthorn, I suggest for your descent you go via Gimmelwald to experience the thrilling swing of the cablecar beyond the cliff over 3000 feet of nothingness below. You are likely to see paragliders from the cablecar—you may even be above them. You will end the cablecar ride at Stechelberg and take a bus the short ride back to Lauterbrunnen, but it is better to walk. And you may see more paragliders this way, or even have one or more land right near you.
I am suggesting you stay in Lauterbrunnen as that makes it easier to do multiple activities, especially the Grindelwald ones, but you could also stay above the valley in Wengen. Then you are closer to Grindelwald by the cablecar/gondola route over the Männlichen ridge.
Wherever you start (Lauterbrunnen or Wengen) I suggest you take the Männlichen cablecar up and either walk the easy scenic trail to Kleine Scheidegg for the train down to Grindelwald, OR skip the walk and take the gondola near the Männlichen cablecar to station directly down to Grindelwald. You can buy tickets for either option.
In Grindelwald, you walk through town to the First gondola and ride that up for the Grindelwald Cliff walk and/or the hike to Bachalpsee. If it is near lunchtime, you can either stop in town for a bite, or ride the First gondola partway up to Bort and have lunch at the mountain inn there before re-boarding the gondola to ride to the top.
Here is a good description of the best way to approach the Grindelwald cliff walk:
You can return from Grindelwald to Lauterbrunnen by train through the valley instead of going back over the ridge, if you like. It may be cheaper and faster—-I don’t recall.
Here is a map of the Swiss rail system so you can plan your route: