
I'd agree that consistency is key but I don't ever ask any friends to give my dog commands unless they're my dog trainer buddies. General public tends to do things like repeat commands over and over and forget to give release commands. :) For my guests I just ask that they don't give my dogs attention for bad behaviour like jumping up or begging. If I want the dog to sit for them I ask them to do it myself, then my company can give the dog a treat and I release it when I'm ready.
As for bombing around he's a baby and enjoying life. Unless he's in danger let him run. For the nipping direct it onto a toy; throw him ragger rope, ball, something else he can get excited with other than your hands or trouser legs. Usually I just cheer them on, after a couple laps around the garden they usually stop. 9 weeks old is so young I wouldn't expect focus for more than a few seconds. He sounds lovely. :)