What I'm wondering is if the friction in the steering mechanism is enough to be able to release the tiller for a while without veering of course? I understand if you have to keep your hands on it att all times when sailing, due to the higher rudder forces, but it seemed to be so light that it'd be a problem even when pedaling.
It's similar to steering a car. Apart from minor adjustments, the boat should tend to keep travelling in a straight line with no input from the rudder. If anything, in the AI, there's too much friction in the system, which allows the rudder to remain deviated when the tiller is released. Ideally, you should be able to let go of the tiller and the rudder should point straight back. If you are having to consistently deviate the tiller to hold a course, it may be a signal that you are experiencing weather helm and need to ease or furl the sail. It probably doesn't matter that the rudder flops to the left in the TI when the boat is out of the water as that could be caused by even minor imbalances. Once the boat is moving through the water, the rudder should center itself.