A cable car to the castle would be on a hiding to nothing for half of the year with English Heritage at the other end.
How about a Formula 1 Grand Prix? Start and finish on Townwall St, turn right at swimming pool, past the White Horse (premium rates for a seat in the window!), up Castle Hill to the roundabout, down Jubilee Way and along the seafront to the clocktower for a good view from the yachts in the harbour, over the swingbridge, back along Snargate St to the start/finish and the pits behind the Gateway.
Don't scoff, there's nothing in that idea that isn't done on the existing circuits already
