Meh... 8 and 4, maybe. I drive a manual, so mostly 8, and gearshift I guess. Move my hands around as I get tired of holding the wheel that way.
Steering wheel safety is overplayed. I think the whole thing is borne of teenagers laying back in the seat steering with their foot or knee or something to be cool/silly, and then going off a cliff or whatever. You hear of plenty of accidents where they "lost control of the vehicle", but I can't for the life of me remember EVER hearing of an accident where it was caused by "driver not holding the steering wheel right". Maybe it happens a lot, and they just never write it up that way. I don't know...
The "don't let the airbag break your arms" has some merit to it. However, the accelerometers are programmed to a relatively high degree of lawyer-proofness and will only set it off in very specific circumstances where the crash is going to hurt you more than the airbag going off will. If your hands are on the wheel, it's going to slap them out of the way, and do it hard. Although fingers to the outside of the wheel will offer less resistance to the bag as it goes off.
If you're actually turning the wheel enough to be going hand-over-hand, by default you're going 25mph or less, parking, doing a right-turn etc., or your vehicle has an extremely lousy steering ratio, or you're in a Tokyo Drift competition or Euro style road-rally on dirt. If you turn that hard at the speeds likely to kill you, you're probably already in the process of crashing/dying.