there is a few things i would like to add to the above.spin recovery including flat spins and the ability to recover the aircraft from any attitude in a precise and controlled manner.when i flew my first twin back in 73 not many twins were being flown back then and i was on my own.i practiced about a month before the test flight doing basic pattern manuvers,especially rolls and spins,inverted flight and landings by cutting the power at anytime during a manuver and landing on one try without touching the throttle.all of this practice was worth it as that scracth built twin still survives today.