Welcome to MySwissAlps!
1. The boats do have heating for the covered areas but there are no outdoor heating on deck. Thus, taking a boat trip in the evening might be too cool and dark outside.
2. You can buy the tickets in advance but you don't have to,please read:
Be sure to check this:
3. You should be able to spend 3 hours or so on Mount Titlis, from there you can head back to Lucerne, please take a look at the below links to help you plan.
Please check this out:
4. Here is a timetable for train for your reference to help plan your daily trip, and a description of how to reach Stanserhorn:
www.myswissalps.com/ti metable, www.myswissalps.com/st anserhorn/gettingthere
5. You can catch the train from Lucerne to Zurich, and the duration is approximately 1 hour. Please refer to the timetable I mentioned.
Here are some links for Lauterbrunnen to give you ideas:
I would advise to buy the ticket ahead of time to make your traveling one less thing to think about. Here is the link about the Swiss Travel Pass:
Once you purchased the Swiss Travel Pass for 3 consecutive days, there is no need to make reservations on regular trains and mountain routes. Seat reservation is only necessary for a few special panoramic trains: https://www.myswissalp s.com/train/reservatio ns.
I hope that helps!