Automatic transmission, service and shift point

Service:
I'm planning this winter's DIY service by going through the "Maintenance and lubrication schedule", and I plan to go by the book. Lucky for me, most items were done recently at Ferrari at seller's expense, so probably only a week's work this winter. I knew that Ferrari are tight on service, but the Dexron III in the automatic transmission, it says to replace oil and filters "at least once per year", that does seem a bit excessive to me. Any views on that? Just do it?

Shift point:
Any big lazy American hi-torque car seems to go into top gear quite early. I know that this is not a big lazy American, but it has lots of torque, but often mine only goes into top gear around 75km/h. Is that in any way adjustable?