It's good to see that you are feeling positive about the cable car proposal, now what's this I hear through the grapevine about the starting point of said cable car ie the cruise terminal at Western Docks? Okay, it will avoid the town completely (but the majority of tourists do when visiting said castle). Think about it though, Wow! it would look fantastic for the town when you take in mind the two cable car routes in Barcelona (which bring in added revenue to the city).
Are the powers that be who will be operating the cable car going to give a proportion of every ticket for riding to the castle & back to the terminal? Hmmm I don't think so, it would be worthwhile deducting monies at source ie once sold the percentage of each ticket goes back to Dovers coffers immediately transfered via BACS.