>> first visit to Switzerland next June … Suggestions for best use of time in Wengen? We'll want to do some hiking some/most days.
The higher trails often don’t open until the second half of June, but you can check with the local tourist office re which trails are open when you are there.
>> Any ideas for the next half day before we head to Wengen?
You can look for ideas on the Luzern page, and work out how feasible they are, given your time constraints, by using the Swiss Timetable. You could leave your luggage in the lockers at Luzern station:
>> Is Glacier 3000 a worthwhile trip in the summer?
From Wengen, it would take 4 to 4.5 hours travel time each way. Whether that is worthwhile is something to decide for yourself :-)
>> Any must see villages etc nearby?
Mürren, Grindelwald and the Lauterbrunnen Valley of course, as well as Wengen.
In addition to the wealth of information in Kim's documents about Wengen (to which rockoyster supplied the link above), other ideas are here:
www.myswissalps.com/ju ngfrauregion/activitie s
One of the scenic PostBus trips might interest you. I have written trip reports about them:
Round trip from Meiringen over 4 passes of the Central Alps (runs 23 June to 14 October 2018)
Grindelwald to Meiringen over the Grosse Scheidegg (or vice versa) (runs 19 May to 21 October 2018)
>> Was thinking an 8 day Swiss Travel Pass each, haven't crunched the numbers yet but would that seem overkill or worthwhile?
If you will be out-and-about every day on trains, buses, cable cars or boats, a Swiss Travel Pass is likely to save you a lot of money. However, there is only one way to know for sure: add up the full-fare cost of all trips you intend to do by train, bus, cable car and boat and compare the total cost with the cost of doing the same trips with a Swiss Travel Pass or other pass.
There is information and a spreadsheet here to help you:
www.myswissalps.com/tr ain/ticketspasses/prac tical/chooserailpass