I just compared travel times for all the top sights of Berlin according to the website below for the DeLuxe appartment and the Gasometer one. If I haven't screwed up completely the results were totally different than the ones I expected.
http://www.visitberlin.de/en/article/berlins-top-10-attractions
According to Google maps, this spreadsheet shows the time needed to reach the different places via train usage from the given appartments. In case of Deluxe I have used Brückenstraße, Berlin as location because there is no exact address on airbnb. The used point is quite central within the circle shown at the airbnb site though.
Update: Serdin and the missing sights included
Update2: Averages included
Okay, so to re-estimate this:
1) Let's drop Kurfurstendamm -- I think it's basically a shopping district and a zoo, which I'm guessing most people aren't super interested in? Maybe just add the Kaiser Wilhelm church (at one end of this district) instead, because that was interesting to see, both historically and architecturally.
2) Group Potzdamer Platz, the Reichstag and the Brandenberg Gate into one trip -- they're all in easy walking distance from one another. That's possibly even a full day's itinerary if you include the spy museum at Potzdamer Platz (I thought it was really well done when I went last year), the wedge-shaped building with the nice look-out, and also the very moving holocaust memorial ("Memorial to the Murdered Jews of Europe") that's just south of the Brandenberg gate, which I don't think was even on your list.
3) The Berliner Dom (Cathedral) and museums are essentially next to each other, so they can be combined. The TV tower is only a 10-minute walk away, so that should probably also be combined into one trip!
4) The Gendarmenmarket is basically the central bit of interesting city, so we're going to want to walk around there, maybe combining with Checkpoint Charlie a little to the south of it? The latter place isn't on your list, but I think it's been mentioned before (at least between me and gkrieg?) when talking about places to visit.
5) I'd be interested seeing the numbers leaving off Charlottenberg palace, given that it's quite a long way from everything else, so could easily be left off the list.
I didn't go to that Berlin Wall Memorial last time (we'd already gone to a free open-air exhibition about the wall and its history somewhere near Checkpoint Charlie), so that's something I'm interested in this time round :-) Maybe faust can suggest what to combine that one with? -- it's farther to the north than I think I explored mostly.
Anyway, I was going to take your table and modify it, but it turns out it's an image, so I can't! :-P