Visit to Switzerland - Need your expertise (Lucerne)

Hi All,
I am visiting Switzerland (Zurich) for 3 nights together with my wife and 4yrs daughter. Our travel dates are as below:

Reaching Zurich: Fri 2 May Protected content
Leaving Zurich: Mon 5 May Protected content

We surely want to cover Rhine Falls, Mt. Titlis, Mt. Pillatus, experience different trains (as far as possible), the cable car and gandola..

Now i need your help/suggestion on:
- how to plan the days so cover above destinations or more (if its better than the one mentioned above)
- any tips on good places (low cost) to stay and tips if the train tickets can be cheaper

Thanks in advance and looking forward to hear from some of you.