Do you have to start the tour right at 9am or is it possible to start at a later time/when you want and still do the hop on and off feature?

You can start the tour at any of the pickup destinations as long as it's before 3:30 if not it will be a waste of money

You can start any time before 3:30pm.. the Trolleys stop running at 4pm. You can get on and off the trolley all day long. It runs about every 20mins stopping at many attractions.

Wonderful experience, We did a full day and loved it.