Hi RonD -
The timetable will help you work out the timing of your plan. It could be quite difficult to do what you are describing, unless you have can spread out some of your journeys over several days. Some of your prposed journeys can make for very long days. I have attached some information on travel times, by way of screen captures.
Take a look at the screen grabs from the timetable - attached - and the Lake Lucerne boat schedule in late October- - linked here, below. I have shown the journey from Brig to the Jungfraujoch, and also a journey from Luzern to Brig via Flüelen. Each shows four journeys at different times.
You might want to consider a base in Interlaken instead of Brig for the Jungfrau and Zermatt. Of course, that would add a bit of time to get back to Visp or Brig for the Glacier Express.
The screen grab of the journey from Luzern via Flüelen shows four versions of a journey chosen with train travel only. In each image I have selected one journey of the four, and expanded it by clicking on the "+" sign to the left of the journey. The default mode is to use the fastest time unless you force it to go via an intermediate stop.
Boat service is limited in the Fall and Winter, and takes about 3 or 4 hours from Luzern to Flüelen. Not sure whether you would be on the Fall schedule or the Winter schedule, since we don't have your dates of travel. Also, it is unclear how much time you plan to spend in Switzerland.
www.lakelucerne.ch/fil eadmin/lakelucerne/con tent/Dokumente_Downloa ds_PDF/01_Fahrplan-Preise/01_Fahrplan/Sai sonaler_Fahrplan/2017/ 2017_Fahrplan_Winter.p df
By the way, the German name of Lake Lucerne is "der Vierwaldstättersee" - the Lake of the Four Forest Cantons.
This map will help you, too:
Zoom in far enough and you can see the train tracks/rail routes.
Milano Centrale is easily accessible from Luzern via the Gotthard Pass route, or from Brig via the Simplon Pass and Domodossola.