(1) Does anyone know whether one can use a credit card to pay for cablecar/funiculaire travel in the Berner Oberland?
(2) We'll be staying in Lucerne the last night, but flying out of Zurich. Is there any advantage to buying a train ticket in this country before going?
Thanks!

I just got back from that area, and if you are asking if you need to buy a ticket from Lucerne to Zurich in advance, no. There are zillions of trains between there all the time, it's only an hour or so. Now there would be the advantage of just having it in advance, so you don't have to worry about doing that at the last minute when you need to be there at a certain time. I don't see any harm in buying one in advance, it's not like you have to get one for one specific train.

I didn't try to use a credit card for the cable cars I took, as the cost was so minimal, so don't know.

How many days are you to be in Switzerland and BOB - a Swiss Railpass can be a good deal with even a few trips as it also gives 50% discounts off all lifts/cables/funiculars, etc.

And good on lake boats on Lake Lucerne, etc.

More details needed. There is also the Half-fare card if you are traveling enough.

A pass or half-fare card is almost always the best choice. Passes are cheaper if bought in US for some reason but Half-fare cards are only sold in Switzerland at stations.

Some cable cars are not cheap - such as the one to Schilthorn in BOB which costs about $80 full fare.

(1) Every cablecar or funicular we have taken has accepted credit cards.
(2) There is no advantage to uying your ticket from Lzern in advance; it is very easy to do there. I believe that the tickets bought in advance (over the internet) are for a particular train, and you would not want to be tied to that plan in advance.

Thank you, all, for those responses!