The future of Charlie is an interesting one.
My own personal view is that a boat ride through a chocolate factory is a good concept, and it's Towers' poor implementation of this that is the issue.
I would start by improving the queueline - a meandering maze queue (especially outside), which could so easily be spruced up by a bit of theming and a few interactive chocolate-themed bits to pass the time for kids (which, after all, is who this ride's primary target audience is).
The ride itself needs more of a chocolate-y scent - a powerful one at that - and the scenes on the actual ride need to be completely overhauled. I've been working on some concepts for how these might be improved for what would be relatively little investment, which I will share if/when complete
(but it revolves around the idea of animatronics, in a similar concept idea to some of the Europa Park rides)
Im personally a fan of the lift section, and think that needs little adjustment (it's the only real thing in the ride which works for me in the way it is implemented as it stands), just needs to be working and well maintained all the time, which it isnt all too often at the moment!
Just a few thoughts from me anyway