V speed in a Seneca:
Vr = 77kts Vx = 76kts Vy = 89kts Vyse = 89kts Vmca = 68kts Vne = 195kts Vno = 163kts Va = 121kts
Hydraulically driven by 2 electric pumps with a 7 second transit.
This depends on weight, C.G., temperature and density.
This altitude is usually where the combination of L/D ratio and engine efficiency are maximized.
Alternate air is an alternate source of air, it can for example be used during ice, when the normal filter is blocked to have a backup source available.
Alternate air is unfiltered air and should not be used during ground operation because the unfiltered air may contain dust and other contamination.
No, you mechanically change a valve that changes the air intake to air that runs past the exhaust manifold and is therefore heated.
The engine will flood with fuel.
Easier for the company in regards to training, maintenance and spare parts as you only use one type of aircraft.