I will file a longer trip report when I'm back home, since my netbook is not working right and is making typing difficult. But I wanted to post a few things while they're still fresh in my mind, that might help others.
1) If you go to Rigi from Luzern by boat, you have a choice of Weggis or Vitznau. Rick recommends going to Vitznau on the way up, then back via Weggis. What he doesn't mention is that by doing this, you avoid a 15-20 minute uphill hike (involving stairs as well as steep pathways) from the Weggis boat dock to the cable car. Going the way he recommends, its a sometimes steep downhill walk that still takes 10 minutes. However, at Vitznau, the cogwheel train is just a few minutes walk from the boat dock. For anyone with even the slightest mobility problems, go both ways via Vitznau (this route is even wheelchair accessible, as I saw the train staff helping someone in a wheelchair onto the cogwheel train to Rigi Kulm, where there are steep but paved paths).
2) In Bern, Rick recommends Tibits, a vegetarian buffet restaurant. But there's also one in Luzern's train station. It's hidden on the top floor, rather than being in the basement like the other eateries. It's handy to know about because it's open Saturday for dinner and Sunday for both lunch and dinner, when Manora is closed (closes at 10 PM Sundays with hot buffet until 9:30 PM, longer hours other days).
3) If you need food after the Coop in the Luzern train station is closed, in the basement on the other end is an Aperto. It's like a 7-11, with a more limited selection and higher prices then the Coop. But it's open until midnight, 7 days a week.