You're giving different options, so it is not easy to calculate your whole stay in Switzerland. Nevertheless, I tried to calculate most of the plans you have. All prices are per person and second class, I used the online travel planner
. All mentioned prices are without discount. To give some examples:
Zürich Airport – Luzern, one way:
CHF 27 Mount Rigi
Return ticket CHF 64
From Lucerne you will have to travel to Arth-Goldau, starting point in the valley. This part of your yourney will cost you CHF 23,60 Titlis
Return ticket CHF 82
From Lucerne you will have to travel to Engelberg, about CHF 32 Pilatus
Return ticket CHF 64
On this site you can also find the costs of other ways of travelling.
All modes of transportation: For this I refer to the online travel planner as mentioned above. Here you can compare different prices, the same goes for the Railway FAQ
Lucerne – Wengen
One way ticket CHF 43,20
Wengen – Jungfraujoch
Return ticket CHF 149
Wengen – Schilthorn
Return ticket CHF 104,20
Wengen – Brienz - Return ticket through Interlaken Ost:
Return ticket CHF 41,60
Just tried to give an example here…
Boat trip Lake of Brienz
Starting in Brienz and ending up there, through Interlaken Ost:
Wengen – Berne
Return ticket CHF 78,40
Wengen – Geneva
Return ticket CHF 156,40
Wengen – Zürich airport
One way ticket CHF 80,20
A Swiss Saver Pass
costs CHF 320 per person, assuming your stay in Switzerland will be eight days, if I read your question correctly. Please view the link to see what discount you will get.
A Swiss Half Fare Card
will cost you CHF 99 per person. Please view the link to see what discount you will get.
The Regional-Pass Bernese Oberland
does not seem like a good idea to me, because most of your plans will not be covered by this Pass.
I have spent my vacations in Switzerland for more than 30 years, but that does not mean I know everything. But I know most of the plans you have mentioned and with the links mentioned above you can do a bit of calculating yourself.
I just want to mention that the Swiss Pass rules for me and my husband! It's all so comfortable, you never have to stay in line to buy a ticket and almost any form of transportation (incl. boats!) is free.
Of course you will have to buy discounted tickets, for cable cars and mountain trains, but believe me, it will be worth your while and you will have discount as well.
A Swiss Half Fare Card might also be a possibility, but if you do a bit of arithmatic yourself, you will find that although this card has lots of discounts, the travel plans you have will most probably be covered by the Swiss Pass.
I wish you lots of fun in Switzerland, and I hope I have helped a little!