First, I think you may be confusing the challenge with normal (re)qualification. For the Gold and Plat Challenges only Q points count, normal (re)qualification can be done with points or miles.

Second, in coach some of the oneworld partners do not give you full AAdvantage miles. You find the details for each carrier in the link I posted in your other thread in the AA forum. Also note that AA code shares operated by oneworld partners give full miles just as any other AA flight.

Third, if you do a RTW, I would suggest you try to pick some interesting places to visit for a few days even if it doesn't maximise your mileage to the fullest. If all you're after is the Platinum status four cheap Pacific mileage runs may be better value than a RTW. Because of the 10-day minimum for a RTW you will have to add a number of hotel nights to the cost.