I agree, keep things simple !
On the subject of Va, Va actually (normally) decreases with a lighter aircraft, so say two up in a 172, Va will be around 95-99kts, where as at max all up weight it'll be around 110kts. The green band probably stretches to 130ish kts in a 172, so lightly loaded you run more risk of causing structural damage by control inputs....
Any maneuvre, such as steep turns, lazy 8's etc., should be entered at or below Va for the configuration to ensure no structural damage can occour.
Cheers
EA
