Old Engineer . . .
I don't think we can deduce much from the given fractional positions of the stick. It could just as well have been given as a percentage or in another base. The stick position will have been converted to a voltage, and the voltage then digitized, for input into the computer, perhaps with some cleanup along the way, before being recorded on the FDR. The fractional notation is for ease of digestion by the reader.
Sampling rates are another issue. Could be anything, from the rate you suggest to some artifact of processing the data. The sampling rate, recorded stick position, and other recorded data are chosen for logical reasons, and would not be limited by the speed of the computer.
Perhaps SensorVal or others would care to elaborate.