This is good advice. Especially Drumheller. You could also check out Dinosaur Provincial Park. I would also add Moraine Lake when you visit Lake Louise but you have to be strategic as it gets really busy
OP you're placing a lot of emphasis on the gondolas but it will take you to maybe 3 hours max then what are you going to do rest of the day? In my opinion the Rockies is for hiking walking and other outdoor activities. If you don't like doing that stuff not sure what the point is other than seeing the views. In this case the time you have allotted for Banff definitely is too much if you're not into hiking.