I'd go with the trolley. The drivers are wonderful, and you won't have the frustration of driving past the things you want to see.
The duck is fun especially if you have kids who aren't equiped for the long walks and waits.
It also sounds like you haven't made unrealistic plans to see everything.
I hope you have a great time. And I thank you, because often when you live near a city you overlook it's richness.
I may just have to plan a trip into the big city soon!