[Brent Mills]

I don't have the answers to all of your questions, but...Rich at idle is likely the mixture screws. When you adjust out the popping, you're actually making the mixture even more rich. I haven't heard of many folks getting rid of the popping (as long as we're talking about letting off the gas and letting the compression slow yo down sort of popping). If you're talking about popping on acceleration, you're lean.