Please help to fine tune the details of the trip

1) If you like to hike, it's definitely worth going to Murren and Wengen on not-so-sunny days. Trummelbach Falls is also a good bad weather day alternative.

2) Yes. That's exactly what we did on our latest trip - we stopped in Wengen on the way up and on the way down, but we only went as far as Kleine Scheiedegg (been to Jungfrau before) and we made the stops specifically to hike.

3) There are loads of them. Suggest you pick up a trail map from a visitor's center when you arrive. I'll look up a few and post later.

4) Yes, but only if you've got the time or a burning desire to see the gorge. It's about a 45 minute train ride and it involves some walking to get to the gorge (about 30 minutes). There's a separate train too, but I'm not sure how that works. It's another not-so-good weather day option as you're with the gorge, so weather isn't that important.

6) You'll have to do the math to see if it's worth it for you. Suggest you add up the cost of all the trips you want to take, add the cost of the Half Fare card (99 CHF) and then go from there.

Regarding #2 - if the weather gods are in your favor, you'll probably want to go to the Jungfrau frist and stop in Wengen on the way down. Clouds can move in at anytime.

Pretty hikes:

From Wengen:

Trail to Hunnenfluh, which begins near the Hotel Belvedere - fabulous views of the valley, Wilderswil and Interlaken, just under 2.5 miles return.

Trail to Staubbachbankli, which begins near the Hotel Baren fantastic views of the valley and Murren - best on a clear day - about 2.5 miles return.

Take the cable car to Mannlichen, walk from there to Kleine Scheidegg.

From Murren:

Take the funicular to Allmendhubel and access the North Face Trail. Gorgeous! Alternatively, you can walk up from Murren, but it's steep. There are several other paths which original from Allmendhubel.

Walk from Murren to Gimmelwald (downhill, easy), take the cable car from Gimmelwald to Stechelberg, then walk from Stechelberg back to Lauterbrunnen or via Trummelbach Falls (paved, level). Alternatively you can walk all the way from Murren to Lauterbrunnen, but the descent into Stechelberg is a bit steep and it's a long walk (3-4 hours total). Or you can walk from Murren to Stechelberg, then catch the bus to Lauterbrunnen.

From Lauterbrunnen:

Take the cable car from Lauterbrunnen to Grutschalp, walk from there to Murren (easy, about an hour).

Walk along the Lutchine (river) from Lauterbrunnen to Zweilutschinen (easy, mostly paved, under an hour). From Zweilutschinen you can catch the train to Grindelwald or back to Lauterbrunnen or Interlaken (or you can keep walking to Wilderswil or Interlaken, or even Grindelwald, but it's a long trek).

From Grindelwald:

Walk from Grindelwald towards Zweilutschinen. This is a long walk, but there are three train stations along the way, so you don't have to commit to the entire walk. Check train schedules before setting out.

Melnq8, thank you so much! Really appreciate you looking into this and giving me such detailed information.
You answered most my questions.
Hopefully, some one will chime in on my question reagarding drive (and stops) from Luzern to Lugano.

Thank you again!

No worries helen63, have a good trip.

There are plenty of options for stops on the drive Luzern - Menaggio. First off, I'd suggest you drive over the Gotthard pass (exit the Autobahn at Göschenen) if the weather is fine. Although not the most scenic Swiss pass it is still much more fun than driving through the tunnel.

Bellinzona is certainly worth a stop. Especially if you're there on a Saturday morning (until noon) when the farmer's market takes place. There is much to see and do in this town: Three castles, two churches, strolling the cobbled alleys in the picturesque old town.

On the other hand, if you want to venture out a little you might consider the following: Take Autobahn exit Lugano-South and drive via Gentilino (Hermann Hesse's grave on the beautiful cemetery) up to Carona, a quaint village with great views and Parco San Grato plus nice restaurants. Continue the drive via Vico Morcote to Morcote (picturesque, great views) and then drive along the lake back to Lugano via Melide, Paradiso etc. and on to Menaggio. It is a very scenic drive and there are plenty of places to stop and have lunch along this route.