Re: Sheet to tiller steering film
I see merit in your system for it makes possible to change the stiffness of the restoring torque provided by the rubber tubing.
I think it would be possible to fine-tune the equilibrium by replacing both bars on the tiller with threaded ones, each receiving a nut connected to the tubing or to the sheet. A small crank at the end of each bar would give you a hold for rotating it. This in turn would move the nut lengthwise and adjust the equilibrium.
I would like to try this system on my own yacht but the tiller is too close to the backstay.