I know a lot of people on the Mazda forums use an oil catch can to trap the oil that gets sucked up into the PCV system, it might be worth looking into.
I watched a video of a guy who removed his intake and found pools of oil just sitting in there (car was almost new). That oil gets plastered onto the back of the intake valves, coating them, leading to huge carbon deposits and misfires. It's becoming an issue with direct injection cars,which I assume the Mazda 3 is. It won't solve your oil consumption problem, but it will keep that oil from going places you don't want it to go.
Google oil catch can for the Mazda 3...plenty of "how to" videos will pop up.